ISLAMABAD , Pakistan ( CNN ) -- Pakistan has indefinitely blocked travel for convoys , carrying food and military supplies to U.S. troops in Afghanistan , through a key mountain pass . Armed militants pose next to a captured armored vehicle near the Pakistan-Afghanistan border . But in a statement , the NATO-led International Security Assistance Force in Afghanistan said , `` We do not expect any impact on ISAF 's ability to carry out operations . '' The decision to suspend travel through the Khyber Pass in northwest Pakistan was taken due to security concerns , said Gula Jan , a security official in Khyber Agency , on Sunday . The mountain pass links Pakistan to its neighbor , Afghanistan . It is in the Khyber Agency , one of seven semiautonomous tribal agencies along the Afghan border . Because Afghanistan is landlocked , many supplies for NATO-led troops fighting Islamic militants there have to be trucked in from Pakistan . Officials said militants aligned with the Taliban and al Qaeda have carried several attacks there . The Pakistani central government has little control in the area , and the area is believed to be a haven for militants . On Tuesday , as many as 60 to 70 armed militants launched back-to-back assaults on convoys . The militants seized 13 trucks -- 12 carrying wheat into Afghanistan as part of a World Food Programme convoy , and one transporting Humvees to the U.S.-led coalition , Khyber Agency officials said . Jan said the decision to suspend travel came after local leaders met with representatives of some of the shipping firms . He said trucks will be allowed through the pass once the security situation improves , but did not specify a date . Dozens of trucks idled by the side of roads Sunday in the Khyber Agency and in Peshawar waiting for the green light . In its statement , ISAF said it has `` multiple , robust and complementary lines of support . '' It added that for security and geographical reasons , `` the movements of civilian convoys destined for ISAF are coordinated with Pakistani authorities and border crossing points . The current temporary adjustments in convoy movements are as a result of this coordination . '' CNN 's Reza Sayah contributed to this report .
NEW : NATO force expects no impact on ability to carry out operations . Pakistan suspends convoys into Afghanistan through key mountain pass . Route was used to carry food and military supplies to U.S. troops . Militants seized U.S. humvees , food aid in ambush earlier this week .