WASHINGTON: The Pentagon has alternatives to the key land routes through Pakistan used to supply US forces in Afghanistan and is not wholly dependent on those routes, a top US official said on Monday.

“We’re confident that we’re not dependent upon any particular single thread, and we can continue to supply the Afghanistan effort,” Ashton Carter, Under Secretary of Defence for Acquisition, Technology and Logistics, told Reuters.

More strains have emerged in already fragile US-Pakistan ties after US forces killed al Qaeda leader Osama bin Laden at a compound near Islamabad, prompting some concerns about the US military's ability to get supplies to troops fighting in land-locked country of Afghanistan.

In an interview, Carter downplayed those concerns, noting that the US military’s logistics operation was developed to deal with unexpected hurdles such as devastating floods throughout Pakistan last year.

“You’ve seen when the volcano hit, when the floods in Pakistan hit, when Haiti happened, that our logistics system was resilient enough and had enough diversity that we could shift load from one mode to another,” Carter said.