The US military has begun withdrawing its troops and equipment from Pakistan’s Shamsi air base under orders from the Pakistan Government after an alleged NATO cross-border airstrike that killed at least 24 soldiers.

A senior Pakistani Army official confirmed: "Two US aircraft landed at the Shamsi airbase today to airlift personnel and equipment ahead of the December 15 deadline set by the Pakistan government for vacating the facility."

The Pakistani troops stationed near the base were put on high alert and necessary security measures were taken in order to ensure safe evacuation, the official added.

Tension between the two nations was aggravated after a strike on two Pakistani military posts, after which 11 December was set as a deadline for the US to vacate the airbase in Balochistan.

The Pakistani Army chief general Ashfaq Parvez Kayani has also warned that any future aggression will result in the country responding "with full force, regardless of the cost and consequences".

The nation also closed routes for Nato supplies to US and allied forces in Afghanistan and decided to boycott the international conference on the future of Afghanistan in Germany.

The US President Barack Obama condemned the attack but did not claim any responsibility and reiterated his commitment to a full investigation.

Shamsi air base, located in the Washuk district of Balochistan, has been used by the US since late 2001 for launching air strikes in Afghanistan, and was also used as a base for the US drone programme.

More than 70 US Marines and Central Intelligence Agency (CIA) operatives have left the base.