US apologizes for chopper strike

Officials seek damage control after raid kills Pakistani troops

ISLAMABAD - The United States has apologized for a fatal helicopter strike in Pakistan as it presses Islamabad to reopen a key border crossing to Afghan-bound NATO supply trucks that have come under repeated Taliban attack.

Thousands of oil tankers and supply vehicles have been stranded in Pakistan for more than a week, waiting for the route to reopen to supplies heading for the 152,000 US-led troops fighting a nine-year war in Afghanistan.