The United States has affirmed Pakistan’s “right to defend itself” after Islamabad reported major clashes with Afghanistan’s Taliban rulers.

A State Department spokesperson said: “The United States supports Pakistan’s right to defend itself against attacks from the Taliban, a Specially Designated Global Terrorist group.”

Washington regards the Afghan Taliban as a terrorist organisation and considers Pakistan a key non-Nato ally. A US official, speaking on condition of anonymity, told Reuters that Washington “does not view Pakistan as the aggressor in the latest escalation” and noted Islamabad is under pressure to address its security challenges.

The latest fighting began after Pakistan launched airstrikes on Afghan territory last weekend, prompting retaliatory Afghan attacks along the border. Islamabad says the strikes targeted Tehrik-e-Taliban Pakistan (TTP) militants operating from Afghanistan, who it accuses of waging an insurgency within Pakistan.

Afghanistan denies harbouring the TTP, arguing that Pakistan is deflecting blame for its own security failures.

More than 331 Afghan Taliban forces have been killed and over 500 others wounded during the ongoing military strikes in Afghanistan, according to Pakistan’s information minister, Attaullah Tarar.

Pakistan carried out air and ground attacks in Kabul, Kandahar, and other towns, reportedly destroying military installations and posts, including 102 Afghan posts, 22 captured positions, and 163 tanks and armoured vehicles at 37 locations, according to Pakistan’s information minister. Afghan officials described civilian areas as also being hit, with at least 11 people killed.

On Friday, the Afghan government said 55 Pakistani soldiers were killed during its strikes, and Afghan losses were far lower than Pakistan claimed.

On Saturday, Pakistan’s state-run media reported the country’s air force carried out strikes targeting key military installations in various areas of eastern Afghanistan.

According to Pakistani authorities, hundreds of residents living near the northwestern Torkham border crossing have fled to safer areas. In recent days, Pakistan has also transported dozens of Afghan refugees who had been waiting at the Torkham crossing to return home to safer locations.

Pakistan’s defence minister Khawaja Muhammad Asif wrote on X: “Our cup of patience has overflowed. Now it is open war between us.”

Afghan Taliban interior minister Sirajuddin Haqqani warned the conflict “will be very costly” but said Afghan forces had not deployed beyond those already engaged. The Taliban emphasised their reliance on guerrilla tactics, stating they had defeated “the world, not through technology, but through unity and solidarity”, despite lacking conventional air capabilities.

Diplomatic efforts are underway to prevent further escalation. Afghan foreign minister Amir Khan Muttaqi spoke with Qatar’s Mohammed bin Abdulaziz Al-Khulaifi to maintain dialogue and reduce tensions. Qatar, which mediated previous ceasefires, is coordinating with Saudi Arabia, Turkey, China, and other countries to defuse the crisis.

The European Union’s foreign policy chief Kaja Kallas called on both sides to de-escalate and stated that Afghan territory “must not be used to threaten or attack other countries”, while urging Afghan authorities to act against terrorist groups.

The United Nations also expressed deep concern about the civilian impact.

Spokesperson Stephane Dujarric said UN secretary-general Antonio Guterres “calls for an immediate cessation of hostilities, and he reiterates his call on the parties to resolve any differences through diplomacy”.

Nearly half of Afghanistan’s population, approximately 22 million people, need humanitarian aid, and the figure could rise if the fighting worsens.

The conflict traces back to long-standing tensions over Pakistan’s allegations that the Taliban provides safe haven to TTP militants.

Border skirmishes in October killed dozens until a Qatari-mediated ceasefire took effect, though subsequent talks in Turkey failed to produce lasting solutions. The renewed fighting marks one of the deepest Pakistani incursions into Afghan territory in years and raises the risk of a protracted conflict along the 2,600-km frontier.

Both sides have signalled a willingness to negotiate. Taliban spokesperson Zabihullah Mujahid said: “The Islamic Emirate of Afghanistan has always tried to resolve issues through dialogue, and now also we want to resolve this matter through dialogue.”

However, Islamabad has insisted that any new provocations or attacks will be met with a “measured, decisive and befitting response”.