In a letter to Pakistan's army chief Ashfaq Kayani, Admiral Mullen, US Chairman of the Joint Chiefs of Staff, has expressed his condolences over the killings of two Pakistani border troops in a NATO helicopter strike.
Dozens of oil tankers have been torched in Pakistan
Admiral Mike Mullen also said on Thursday that senior commanders would review the investigation into the incident with a view to "avoiding recurrence of a tragedy like this."
On Wednesday, the US Ambassador in Islamabad, Anne Patterson, had already apologized for the September 30 strike, in which chopper pilots apparently mistook the Pakistani soldiers, who fired warning shots, for militants attacking them.
Angry reaction from Islamabad
Pakistan reacted angrily to the infringement of its borders and killing of its troops and closed the Torkham border crossing, near the Khyber Pass, the same day. This is NATO's main supply route to Afghanistan. Islamabad cited security reasons to justify the move but it was widely seen as a punitive measure to apply pressure on NATO.
Most NATO supplies get to Afghanistan via the Khyber Pass
There has since been a wave of arson attacks on NATO convoys in Pakistan, which the authorities have blamed on Taliban rebels. They have served to underscore the vulnerability of the NATO supply lines in Pakistan.
In the latest attack of this kind, suspected militants torched 54 NATO oil tankers in the north-western town of Nowshera.
Most observers agree that Pakistan has basically got what it wanted, and that the US apologies, as well as the assurance to prevent similar incidents in future, should pave the way for the border to be reopened soon.
But Pakistan's foreign ministry spokesman Abdul Basit told journalists on Thursday that there had been no decision yet on reopening the Torkham crossing. He went on to condemn the growing number of US drone strikes in Pakistan's tribal areas, saying there was "no justification" for them.
Thomas Baerthlein (AFP/dpa/Reuters)
Editor: Anne Thomas