The United States is evacuating a Pakistani air base following orders from the military incensed by a deadly NATO raid on its border that left 24 of its soldiers dead, officials said.
Pakistan's top command ordered the US out of Shamsi air base in the wake of the 26 November bombing. The base is widely understood to have been a hub for the covert CIA drone war on Taliban and Al-Qaeda commanders in the northwest.
US Ambassador to Islamabad Cameron Munter told a Pakistan television channel on Monday: "We are complying with the request."
The deadline for the removal of all US personnel and equipment from the base in the remote southwestern province of Baluchistan was set for 11 December.
"They are evacuating the base; evacuation is in the process," confirmed a senior Pakistani government official in Islamabad.
"Pakistan has provided security to them (Americans) on the Shamsi air base and we will withdraw that security from the date we have given for withdrawal, so they have no other option but to evacuate it," the official said.
Islamabad has so far refused to take part in a US investigation into the deadly air strikes on the Afghan border.
In the wake of the strikes, Pakistan decided not to take part in the Bonn Conference on the future of Afghanistan, which, along with the Taliban's boycott, cast doubt on any hopes of using the meetings to pursue a peace settlement.
Pakistan has also shut down a key NATO supply line into Afghanistan along with its order for American personnel to leave Shamsi air base.
US President Barack Obama on Sunday expressed condolences to Pakistan's President Asif Ali Zardari for the soldier deaths and said the NATO airstrikes that killed them were not a "deliberate attack."
But the incident has plunged relations between Washington and its counterterrorism ally Islamabad to a new nadir, although officials say neither country can afford a complete break in relations.
US officials and intelligence analysts have said the covert drone war would not be affected by closure of the base as Washington could fly Predator and Reaper drones out of air fields in neighbouring Afghanistan.
But the Shamsi air base is supposed to be particularly useful for flights hampered by poor weather conditions.
Islamabad has tacitly consented to the covert US drone campaign, which many Pakistanis see as a violation of their country's sovereignty.