NEW YORK — The United States hopes to move 60 per cent of its accumulated military hardware out of Afghanistan by way of Pakistan as American troops begin their withdrawal after 11 years of the stalemated Afghan war, according to a media report.

In a dispatch published in its Friday edition, The New York Times underlined the enormity of task of transporting more than 600,000 pieces of equipment valued at $28 billion, saying getting 34,000 troops out is the easy part.

In US arsenal are systems that always present challenges to international shipping, including MRAP mine-resistant troop transports and Stryker infantry fighting vehicles, each built with tons of armour, and heavy tractor-trailers and tankers, the dispatch said. The effort requires Pakistan to keep border crossings open permanently.

So far, the paper said, the heavy vehicles have all been shipped out by air because Afghanistan is landlocked, it has a primitive road system and the Taliban remain strong in many parts of the country. “But the real problem to withdrawing from Afghanistan is the same one that has helped make fighting there so difficult: the tenuous relationship with neighbouring Pakistan, which offers the cheapest land route to the closest seaport but through border crossings that are unreliable.

“Logistics officers are only too mindful that Pakistan closed the routes after American airstrikes killed 24 Pakistani soldiers at an outpost on the Afghan border in November 2011. The routes were reopened only last July after Washington apologised. But American officials hope that up to 60 per cent of the hardware in Afghanistan can be sent out by way of Pakistan.”

As President Barack Obama delivered his State of the Union address on Tuesday night, almost 40,000 armoured or other large vehicles remained in Afghanistan, it was pointed out. The military has a goal of bringing out 1,500 of them every 30 days, a target it can reach — in a good month — by air. But there are just 22 months until the American-led combat mission ends in December 2014.

“It is going to be a challenge, requiring Pakistan to permanently open those border crossings, and it is going to be expensive,” the Times said.

The US military has experience of large movements of material, and most of the senior officers involved in pulling equipment from Afghanistan did the job in Iraq. But these officers emphasise that Iraq offered a sophisticated roadway system and flat terrain.

“Afghanistan is not Iraq, and it’s harder,” Lt-Gen Raymond Mason, the Army’s deputy chief of staff for logistics, was quoted as saying. “No 1, it’s landlocked. And we have no Kuwait. We have no ‘catcher’s mitt,’ no shock absorber. In Iraq, on the last day, you could still send stuff across the border into Kuwait, and absorb it there.”

General Mason said re-establishing with certainty a pair of ground crossings into Pakistan would allow a larger volume of equipment to make a faster exit from Afghanistan; the gear would be driven to Karachi, and then shipped by sea back to the United States. He said the first containers of hardware leaving Afghanistan had been driven into Pakistan just in the past few days. “That’s the good news,” he said. “But it is still very fragile.”

Maj-Gen Kurt Stein, commander of the First Theater Sustainment Command, in charge of logistics across the Middle East and Southwest Asia, said there was another land route out of Afghanistan, called the Northern Distribution Network, which runs north through Central Asian republics. But the initial land portion is inconveniently long as it strings toward ports on the Black Sea, the Mediterranean and Atlantic, and presents its own challenges: railroads are of different gauges, and there are prohibitions on shipping lethal cargo.

Regardless, the movement north from Afghanistan requires passage through the Salang Tunnel, dug into the mountains of Parwan province. The tunnel was a favourite of insurgent ambushes during the Soviet invasion and withdrawal. And, today, American troops are not deployed in Afghanistan’s north.

“About 85 to 90 per cent of our equipment is south and east of the tunnel,” General Stein said, noting that the military never relies on what officers call “a single point of failure” like the lone and vulnerable tunnel on the northern exit route.

General Stein, who is based at Fort Bragg, spoke from his forward headquarters in Kuwait, and also has a second forward hub in Afghanistan. He has travelled the region inspecting ports, and has met with transportation executives to accelerate the effort.

In response to queries on the retrograde effort, the military’s Transportation Command said the recent shipments through Pakistani border crossings were a test — “proofs of principle shipments” — to gauge whether the routes can be dependable.

But problems arose. The immense backlog of 7,000 containers that had piled up during the Pakistani closing still had to be reduced. Officials had anticipated starting dry runs for withdrawal — essentially running trucks through the border crossings — in January. But labour strikes by drivers, squabbles between Afghan and Pakistani custom offices, and internal disputes among Pakistani bureaucracies delayed the initial phase until last weekend, the dispatch said. Similar tests of cargo routes are being conducted along the Northern Distribution Network.

Transportation Command officials said major transit hubs, in addition to Karachi, would include ports in the United Arab Emirates, Romania and Spain.