The US operation to remove military hardware and vehicles from Afghanistan as troops withdraw after 12 years of war will cost between five and six billion dollars, officials said Sunday.

Among statistics released by the military about the process known as a "retrograde" was that 25,000 vehicles have been shipped out of Afghanistan in the last year and another 25,000 remain in the country.

About 100,000 containers are also still in Afghanistan, and will be used to remove mountains of equipment ranging from fighting gear to fitness machines, furniture and computers.

"The retrograde from Afghanistan is one of the most challenging military transportation operations in history in terms of scale and complexity," Brigadier General Steven Shapiro said in an email.

"Our number of vehicles in Afghanistan has dropped by nearly half in the past year."

Shapiro, the commanding general of 1st Theater Sustainment Command, said decisions were being made on what equipment was left for the Afghan army and police to take on the fight against Taliban insurgents.

"Ground commanders are able to nominate this equipment as they assess the needs and maintenance capabilities of their Afghan partners and numbers will vary," he said.

"The figures of five to six billion dollars corresponds to the total cost of retrograde from 2012 through 2014, and they're constantly being reevaluated."

Most of the hardware will be flown out of land-locked Afghanistan or taken by road to the Pakistani port of Karachi, though the route has been hit by militant attacks and was temporarily closed by spats between Washington and Islamabad.

US hands over Afghan district after 'abuse' row
Kabul (AFP) March 30, 2013 - The US military pulled out of a strategic district in eastern Afghanistan on Saturday as part of a deal with President Hamid Karzai, who alleged that soldiers had mistreated locals.

Karzai had at first accused Afghan militia working with elite US units of torturing and murdering civilians, but later changed his allegations to focus on unproven claims of "harassment" by American troops.

The president issued an ultimatum that US commandos leave the province of Wardak, a key region close to the capital Kabul, raising concern that the pullout would create a major security opening for Taliban insurgents.

A compromise deal was reached in which US troops would leave Nerkh, one of Wardak's eight districts, as the US and Karzai tried to smooth over a series of damaging public rows.

"Our forces have transitioned Nerkh district to Afghan National Security Forces and they have now assumed full responsibility for security in this key district," General Joseph Dunford, commander of the US-led coalition, said.

"The rest of Wardak will continue to transition over time as Afghan forces continue to grow in capability and capacity," he added in an emailed statement.

Relations between Karzai and Washington were badly frayed recently as the bulk of NATO's combat soldiers get ready to leave by the end of next year.

The United States, which provides 66,000 of the 100,000 total troop deployment, was stunned by Karzai's accusations earlier this month that the US worked in concert with the Taliban to justify its presence in the country.

The Afghan president's spokesman also described the coalition war effort against the Taliban as "aimless and unwise".