The US has said it is working with authorities in Pakistan to clear the backlog on the Afghan supply routes, which were reopened this month.
"We're working with our Pakistani counterparts to move ahead and clear that backlog," state department spokesman Patrick Ventrell told reporters at a news conference.
But there is no time frame as to when these backlogs would be cleared, he noted.
"We've already seen several containers move across the border into Afghanistan. We also understand that the process of activating the supply routes has only just begun and that it will take time for the backlog to be cleared," he said.
"There are some residual technical arrangements we’re working on, so we continue discussions with the Government of Pakistan to this end," Ventrell said.