The rerouted supplies, like all that go through Pakistan, are non-lethal items.
Closing the border is among a series of actions Pakistan took in response to the Nov. 26 incident, for which the U.S. has expressed regret but not apologized. The Pakistanis refused an invitation to participate in a U.S. Central Command investigation of the killings, and they boycotted an international conference in Bonn, Germany, this week on sustaining financial and political support for Afghanistan.
A Pentagon spokesman, Navy Capt. John Kirby, said the border closing has had "no appreciable impact" on military operations in Afghanistan and that senior American commanders believe they are well supplied for now.
Kirby said the top U.S. commander in Kabul, Marine Gen. John Allen, is "comfortable that he's got what he needs right now."
About 30 percent of the non-lethal supplies for U.S. and coalition troops in Afghanistan normally come via two routes from Pakistan the Torkham border crossing in the northwest Khyber tribal area and at the Chaman gateway in the southwestern Baluchistan province, near the city of Quetta. Much of what is supplied is fuel.
About 40 percent of non-lethal supplies travel on a northern route that enters Afghanistan by rail through Uzbekistan, and about 30 percent are shipped by air.
Pakistan has not said how long it will keep the border closed. After previous incidents, including an attack a year ago by a U.S. helicopter that killed two Pakistani soldiers posted on the border, the crossings were closed for 10 days to two weeks. U.S. officials believe the closure will last longer this time.
Aware of its vulnerability to unpredictable Pakistani border closings, the U.S. military in recent years has developed alternative supply routes. In particular it has expanded the capacity of the northern route since 2009. With a troop drawdown now under way in Afghanistan, supply requirements are expected to fall, thus also reducing the need to send fuel and other materials by land across Pakistan.
Kirby described U.S.-Pakistani military relations as being in "a very tough spot." Noting that Pakistan on Tuesday recalled some troops from border posts meant to coordinate activity with international forces in Afghanistan, Kirby said the U.S. and its NATO partners hope they will return soon.
"The whole reason those centers exist is to help try to prevent incidents like what happened" Nov. 26 on the border, he said. "The risks (of miscommunication and mistaken attacks) only increase when you don't have those coordination centers fully manned and staffed."
The closing of the border and other Pakistani reactions to the border incident have again raised questions in Congress about the future of U.S.-Pakistani relations.
Republican Sens. John McCain of Arizona and Lindsey Graham of South Carolina said Monday that Washington should reconsider the relationship. They called the Pakistani soldier deaths a "terrible tragedy" but said Islamabad's response was "deeply troubling" and has added to the deterioration of the relationship.
"In particular, all options regarding U.S. security and economic assistance to Pakistan must be on the table, including substantial reductions and stricter standards for performance," they said in a joint statement.
Sen. Dianne Feinstein, D-Calif., told reporters Tuesday that legislation putting new restrictions on aid to Pakistan would have a "good chance" of passing Congress.
How long will border be closed?
Pakistan has not said how long it would keep the border closed. After previous incidents, including an attack a year ago by a U.S. helicopter that killed two Pakistani soldiers, the crossings were closed for 10 days to two weeks. U.S. officials believe the closure will last longer this time.