PESHAWAR, Pakistan | Pakistan closed the main route used to ferry supplies to U.S. and allied troops in Afghanistan on Tuesday after launching a fresh offensive against militants in the Afghan border area.
Although the exact length of the closure isn't known, the U.S. already has started looking for supply-line alternatives as it prepares to almost double its number of soldiers in Afghanistan next year.
A U.S. military spokesman in Afghanistan welcomed the operation against the extremists, despite the suspension of the supply route.
"We are glad that they're helping clean out what they call miscreants in that area that have been attacking the supply line," said Col. Greg Julian. "Temporary closure [of the supply line] is not a problem. It's best that they conduct this operation and clear out these trouble spots."
The road through the Khyber Pass in northwestern Pakistan has come under increasing attacks by militants seeking to squeeze Western forces fighting a resurgent Taliban in Afghanistan in recent months.
U.S. and NATO soldiers in landlocked Afghanistan rely on the winding, mountainous route for delivery of up to 75 percent of their fuel, food and other logistical goods, which arrive in Pakistan via the port city of Karachi.
American commanders insist that the attacks are not disrupting their mission in Afghanistan. Although they are exploring new routes, they say they have enough supplies to last many weeks in case the routes are blocked.
But the U.S. next year will send up to 30,000 new forces to the country to reinforce the 32,000 American troops already there, requiring even more support and supplies.
Last month, the Associated Press reported that NATO was close to reaching deals with Central Asian countries north of Afghanistan that would allow the alliance to truck in "non-lethal" supplies from there.
It has already reached a similar agreement with Russia that remains in force despite tensions triggered by the Georgia conflict earlier this year, NATO officials said.
Tariq Hayat Khan, a top administration official in the Khyber area, said security forces were battling the militants using helicopter gunships and heavy artillery.
Gunmen have staged a series of raids on truck depots near the Pakistani city of Peshawar in recent weeks, killing several guards and burning hundreds of vehicles, including dozens of U.S.-bought Humvees destined for the Afghan army.
During the summer, militants attacked and torched dozens of U.S. supply trucks on Afghanistan's main highway.
A smaller number of supplies arrive in Pakistan by a second land crossing at Chaman in the southwest. That road was open Tuesday, a witness said.
Meanwhile in the Afghan capital, Kabul, the U.S. ambassador released grim statistics that underscored the country's deteriorating security situation.
The number of roadside bombs rose from roughly 1,000 in 2007 to 2,000 in 2008, while the number of kidnappings jumped from about 150 to 300, said Ambassador William Wood.
Speaking at an end-of-the-year press conference, Mr. Wood called 2008 a "good year but also a hard year."
The Taliban in the past year has pushed into remote areas of Afghanistan where the government has little presence and where Afghan and international security forces rarely reach. To counter that, the U.S. will soon begin a pilot program to train Afghan tribal members selected by their local leaders to help defend their villages, Mr. Wood said.
The ambassador stressed repeatedly that the U.S. would not provide any weapons for the community defense program and that the program wasn't the re-creation of tribal militias. He said that Afghanistan has always depended on local groups to defend their communities and that President Hamid Karzai asked the U.S. to strengthen villagers' defense initiatives.