Trucks supplying Nato in Afghanistan crossed the border from Pakistan for the first time in seven months after Islamabad reopened transit routes.
Pakistani officials said at least two Nato containers passed through the Chaman border point on Thursday.
Many more lorries remain in the southern Pakistani port of Karachi awaiting clearance to proceed.
Pakistan reopened the routes after the US apologised for killing 24 of its soldiers on the border in November.
The decision will save the US hundreds of millions of dollars as it prepares to withdraw from Afghanistan.