The Defense Department is shuttering key supply lines in Pakistan, ordering a halt to all military shipments along those routes.
The decision was prompted by security concerns for military and civilian shipping firms moving along the routes, Pentagon spokesman Mark Wright told Reuters on Tuesday.
"We anticipate we will be able to resume our shipments through this route in the near future," Wright said.
The supply lines running through Pakistan are critical to U.S. and allied commanders, who depend on those routes to facilitate the American withdrawal from the country next year.
Washington is turning up the heat on Kabul to formally agree to a postwar plan that lays the groundwork for a U.S. presence in the country after the 2014 deadline.
On Monday, Pentagon announced the U.S. and Afghanistan have until late February or early March to reach a deal on a security agreement, or risk having no American troops in the country after 2014.
NATO chief Fogh Anders Rasmussen said Tuesday the alliance may have also have to pull out of the country completely, if a postwar deal is not reached.
Washington has been pressuring Afghan President Hamid Karzai to approve the postwar plan by the end of the year.
But the Pentagon says it will provide some flexibility on the deadline for a final deal.
“Dec. 31 is not a hard and fast date,” Defense Department spokesman Col. Steve Warren said
But U.S.military leaders are adamant that time is running out for Karzai to approve the pact.
American and NATO supply trucks have been stranded along the contested supply lines near the Afghan-Pakistan border, after protesters blocked those routes in an attempt to end U.S. drone strikes in the country.
Roughly 1,500 trucks, loaded down with equipment and supplies bound for U.S. and allied troops in Afghanistan, have been stuck in the volatile northwest provinces of Pakistan for the past three days, due to the protests.
The protest is being led by local leaders in the Khyber-Pakhtunkhwa province, which abuts the Afghan-Pakistan border.
Those leaders voted to cut off the supply lines by Nov. 20 unless Islamabad and the United States can reach a deal to end armed American drone operations.
The vote and subsequent protest came days after Hakimullah Mehsud, the reputed leader of the Pakistani Taliban, and five other Taliban members were killed in a U.S. drone strike inside Pakistan.