Washington: The US military’s drawdown in Iraq and buildup in Afghanistan represents the biggest movement of troops and equipment since World War II, a top general said Friday.

“This is the largest operation, that we’ve been able to determine, since the build-up for World War II,” said Lieutenant General William Webster, who oversees the effort as head of the Third Army.

Webster described a mammoth logistical task in moving 30,000 troops, more than 5,000 vehicles and tons of supplies to Afghanistan, while pulling out equipment and tens of thousands of forces from Iraq — all by a September deadline.

About 2.8 million pieces of equipment are being withdrawn from Iraq as part of a gradual US drawdown underway, and the army has to decide what items can be shifted to Afghanistan, shipped back to the United States or left behind in Iraq, Webster said.

“We began, actually, last June moving equipment out of Iraq, and we’re sorting it out here in Kuwait,” he said by video link from a US base there.

“Some of it goes into Afghanistan; some of it goes back to the army to be reset back in the depots and then returned to our soldiers who are training back in” the United States, he said.

The combined drawdown in Iraq and surge in Afghanistan has been dubbed “Nickel II,” the general said.

The codename plays off the Third Army’s role in World War II, when General Patton ordered a dramatic turnabout to attack the Germans during the Battle of the Bulge. Patton called his operation “Nickel.”

“So when we looked at that operation historically and the size of it, we realized that we were many times greater than that and over a much longer duration,” he said.

While troops and weaponry are transported to Afghanistan by air, tonnes of supplies are ferried over land and sea, either through Pakistan’s port at Karachi and over the Khyber Pass or via Central Asian roads and rail lines into northern Afghanistan.

The US-led force has relied heavily on the Pakistan route, despite repeated attacks on the Khyber road by Taliban militants in the restive tribal areas along the border with Afghanistan.

But now about half of all materiel is coming through the “northern distribution network,” Webster said.

Less than two years ago, military officials said about 80 percent of supplies for the NATO mission were coming through Pakistan.

“So those northern routes have given us a great deal of relief and additional capacity, if any of the routes are blocked by weather or enemy action,” he said.

The northern network includes five routes through Central Asian countries, with the longest stretching 8,000 kilometers (5,000 miles) long, he said.

The United States has about 95,000 troops in Iraq and President Barack Obama has promised to scale back the presence to 50,000 forces by September, before a complete withdrawal by the end of 2011.