U.S. airlines began canceling Sunday flights and waiving cancellation and change fees for airports from Virginia to Maine ahead of another massive winter storm on the East Coast, set to once again put carriers to the test at the tail-end of winter break.

Delta Air Lines, American Airlines, JetBlue Airways, United Airlines and Spirit Airlines waived fees and fare differences for passengers if they can travel as late as Feb. 26. Southwest Airlines said customers are eligible for a change without paying a difference in fare if they can rebook to fly or fly standby within two weeks.

The storm could bring between 13 and 18 inches of snow to parts of southern Connecticut and southeast New York, as well as winds of up to 55 miles per hour, according to the National Weather Service. The blizzard warning is set to begin at 6 a.m. ET Sunday.

As of 4:30 pm ET Saturday, close to 400 U.S. flights were canceled, according to FlightAware. Delta had the most, with 174 cancellations or 5% of its mainline schedule. New York airports, which make up a major Delta hub, were the most affected by Sunday’s disruptions.

The National Weather Service raised its initial assessment of the potential severity of a storm. The weather service now says 1 to 2 feet (about 30 to 61 centimeters) of snow is possible in many areas. Blizzard warnings were also issued for New York City, Long Island, southern Connecticut and coastal communities in New Jersey, Delaware, Rhode Island and Massachusetts.

The weather service warned that the storm’s steady winds of 25 to 35 mph (40 to 56 kph) would “make travel dangerous, if not impossible.”

Winter Storm Fern in January, followed by bitter cold, caused mass travel disruptions across a large swath of the U.S.

American Airlines had struggled to recover, drawing harsh criticism from flight crews, some of whom were stranded and had to sleep at airports, heightening tension between frontline employees and the company’s CEO, Robert Isom.

The storm cost American between $150 million and $200 million in revenue, the carrier said last month on an earnings call.

— The Associated Press contributed to this report.

Cuba’s communist-run government is facing its biggest test since the collapse of the Soviet Union.

U.S. President Donald Trump has ratcheted up the pressure on the Caribbean island since the Jan. 3, military operation to seize Venezuelan President Nicolás Maduro, a long-time ally of Cuba’s government. Cuba said 32 of its citizens were killed in the attack.

Trump has since effectively cut Cuba off from Venezuelan oil, called its government “an unusual and extraordinary threat” and pledged to impose tariffs on any country that supplies it with oil.

Cuban President Miguel Díaz-Canel condemned the move and said: “Surrender is not an option.” He’s since said the government is prepared to hold talks with Washington, albeit “without pressure or preconditions.”

The country has warned that international airlines would no longer be able refuel in the country due to fuel shortages. Gripped by a worsening economic crisis, Cuba’s government recently adopted rationing measures to protect essential services and ration fuel supplies for key sectors.

The plan reportedly includes restrictions on fuel sales, the closure of some tourist establishments, shortening school days and a shorter working week at state-owned companies to four days, from Monday to Thursday.

“The current situation in Cuba is as serious as it has been since the 1990s, when Cuba suddenly had to survive without the support of the Eastern Bloc,” Par Kumaraswami, professor of Latin American Studies at the U.K.’s University of Nottingham, told CNBC by email.

Trump’s tariff threats have created a deterrent for many nations, Kumaraswami said.

Mexico has sent humanitarian aid but suspended oil shipments, as it sought to preserve its relationship with Havana while avoiding Trump’s tariffs.

Kumaraswami said there was “of course frustration with the difficulties of daily life,” but that “many Cubans are resolved to resist threats to their national sovereignty and a new wave of patriotism has emerged.”

Air Canada subsequently has canceled all flights to Cuba amid the fuel shortage, though the airline said Monday that it would bring some 3,000 customers already in the country home over the coming days.

Tourism is a significant source of revenue for Cuba’s cash-strapped government and the country is a popular winter vacation destination for Canadian tourists.

Unlike in previous crises, Cuba’s regime lacks foreign partners that can step in to help, according to Robert Munks, head of Americas research at risk intelligence company Verisk Maplecroft.

“Raising the stakes, the US has also limited Cuba’s access to hard currency and pressured Nicaragua to end visa-free travel for Cubans,” Munks told CNBC by email.

The government’s pledge to increase the use of limited renewable energy sources is likely “too little, too late,” Munks said. He added that outbreaks of civil unrest were possible, given that the island’s domestic energy production is far short of what it needs to keep the lights on.

“An accelerating collapse of basic services will put the regime under extreme pressure to find a negotiated solution,” Munks said.

He added that “the odds are shortening” on Díaz-Canel being forced from power in the months ahead in a Maduro-style managed transition, but Munks said it was more likely that “the regime will try to muddle through” until the U.S. midterm elections in November.

Cuba’s dwindling oil supplies prompted the United Nations to warn of a possible humanitarian “collapse” last week.

“The Secretary-General is extremely concerned about the humanitarian situation in Cuba, which will worsen, and if not collapse, if its oil needs go unmet,” said UN spokesperson Stéphane Dujarric.

A spokesperson for China’s foreign ministry said Tuesday that Beijing “stands firmly against the inhumane actions that deprive the Cuban people of their right to subsistence and development.” They added that China would, “as always,” seek to provide assistance to Cuba.

Russia, meanwhile, has described Havana’s fuel situation as “truly critical” and said U.S. attempts to further pressure the country were causing numerous problems.

“The Cuban government is not going to submit,” Yaffe said. “The fact is, [the U.S. is] going to keep squeezing and the Cubans are going to keep resisting and there’s going to be a lot of unnecessary suffering.”

She added: “I’m a historian and it’s very vainglorious for historians to try and predict the future but we can look at trends — and I can guarantee you that we were here before in the early 1990s where nobody thought Cuba would pull together and pull through — and they did.”

American Airlines flight attendants’ union held a picket outside the company’s headquarters on Thursday pushing for new leadership at the carrier, which has lagged rivals Delta Air Lines and United Airlines in profitability and punctuality.

Ahead of the picket on Wednesday night, American CEO Robert Isom sought to calm frustrated employees and listed improvements the carrier expects this year, including a jump in profits as well as improvements to schedules and new cabins.

“We look forward to working with all of you to make it happen,” Isom said in a video message filmed at the airline’s Fort Worth, Texas headquarters.

The picket came days after the Association of Professional Flight Attendants, representing American’s 28,000 cabin crew members, issued a vote of no confidence in Isom, which the union said was its first such move. The chief executive was also criticized by the pilots’ union, which sought a meeting with the airline’s board, of which Isom is a member, to discuss the problems. Unions for pilots, flight attendants and mechanics have all recently said the company needs to do better to improve reliability and financial results.

The protest is an unusual move outside of contract negotiations.

The signals from the labor groups have increased pressure on Isom, who took the helm nearly four years ago, and American’s leadership team, which is investing in cabin upgrades, bigger airport lounges and other on-board products.

Last month, American forecast stronger revenue and profits for 2026 and said it expects to report adjusted earnings per share of as much as $2.70, up from an adjusted 36 cents last year.

American is in the middle of a revamp that it hopes will help revive profits with more modern airplane cabins that command higher fares, which is especially important as coach-class fares have dropped. It has also built bigger lounges and added free Wi-Fi for customers.

For the first 11 months of the year, American ranked eighth in punctuality with a 73.7% on-time rate, according to the Department of Transportation. It is now adjusting its schedules, including at its massive Dallas-Fort Worth International hub where it is spreading out flights more throughout the day.

But it has a long way to go. In 2025, American posted net income of $111 million compared with Delta’s $5 billion and more than $3.3 billion from United. The lower profits meant a smaller profit-sharing pool for employees, which staff members have complained about.

In a town hall with employees last month, Isom noted that American’s pilots, flight attendants and other groups have recently sealed new labor contracts that have meant higher wages compared with their counterparts at rival United. But he said he was disappointed by the profit-sharing.

The flight attendants have also said they were frustrated with American’s struggles to recover from major winter storms, which left some crew members without a place to sleep.

Picketing crew members on Thursday carried signs that said “everything froze, AA melted down,” referring to the disruptions, and “Failed Ops=Failed CEO,” nodding to the carrier’s operation.

“This airline is headed down a path that puts our careers at risk,” the flight attendants’ union said in a notice about the picket. “Now is the time for Flight Attendants to stand together and show up in protest. American Airlines needs real accountability, decisive action, and leadership that will put this airline back on a competitive path.”

Isom is also trying not only to win support of frontline crews but also to rally higher-ups. Last week, at Globe Life Field in Arlington, Texas, Isom spoke to about 6,000 managers about the years ahead as the airline turns 100.

“We’ve filled an entire Major League Baseball field with this proud and talented team. The best in the industry,” he said, according to a transcript of his remarks, which were seen by CNBC. “It’s incumbent on all of us to build on our progress … and to ensure that we grow profitability so American is around for the next 100 years.”

The Cuban government said international airlines can no longer refuel there due to fuel shortages after U.S. President Donald Trump threatened tariffs on any country that supplies the communist country with oil.

The island nation’s leadership said Sunday that Cuba will run out of aviation fuel from Monday, likely disrupting operations airlines operating there, according to EFE news agency, citing two sources.

The kerosene shortage is expected to persist for the next month, with all of Cuba’s international airports affected.

Cuba’s Foreign Ministry and the Cuban Embassy in London did not immediately respond to a CNBC request for comment.

Trump, in an executive order issued at the end of January, said the Cuban government constituted “an unusual and extraordinary threat,” which required a national emergency declaration.

The U.S. president said that Cuba’s ties to countries including China, Russia and Iran, human rights violations and communist leadership destabilize the region “through migration and violence.”

As part of the announcement, Trump said U.S. tariffs may target countries that provides any oil to Cuba, whether directly or indirectly.

The Trump administration has sought to tighten the U.S. chokehold on Cuba since Jan. 3, when it conducted an audacious military operation to depose Venezuelan President Nicolás Maduro, a long-time ally of Cuba’s government.

The plan reportedly includes restrictions on fuel sales, the closure of some tourist establishments, shortening school days, and a reduction of the working week in state-owned companies to four days, from Monday to Thursday.

Russia, which holds friendly ties with Cuba, said Monday that Havana’s fuel situation was “truly critical” and that U.S. attempts to further pressure the country were causing numerous problems.

“The situation in Cuba is truly critical. We know this. We are in intensive contact with our Cuban friends through diplomatic and other channels. Indeed, let’s say the U.S.’s stranglehold is causing many difficulties for the country,” Kremlin Spokesperson Dmitry Peskov told reporters on Monday, according to state news outlet RIA Novosti.

Cuba’s Foreign Minister Bruno Rodríguez Parrilla previously said the country’s leadership condemned Washington’s tariff threats in the “strongest possible terms.”

In a statement posted on Jan. 30, Parrilla also accused the U.S. government of resorting to “blackmail and coercion in an attempt to make other countries to join its universally condemned blockade policy against Cuba.”

Mexican President Claudia Sheinbaum said last week that her government would aim to send humanitarian aid to Cuba from Monday, adding that the country is working to find a diplomatic solution to resume oil shipments to the Caribbean island.

Mexico had paused shipments of crude and refined products to Cuba amid pressure from the Trump administration.