The last of the 33,000 troops sent to Afghanistan in what was called the “surge” more than two years ago have pulled out.

U.S. Defense Secretary Leon Panetta confirmed the withdrawal on Friday. Panetta, during a joint news briefing in Auckland with New Zealand's defense minister, praised U.S. forces, saying the surge “did accomplish its objectives” of reversing Taliban momentum and building up the Afghan force.

U.S. troops levels in Afghanistan are now back down to 68,000 — the pre-surge number and U.S. officials say all allied combat troops are on track to pull out of Afghanistan by 2014.

President Barack Obama ordered the extra forces to Afghanistan in late 2009 to push back insurgents and give Afghan forces a chance to start taking over security.

Still, concerns remain that the withdrawal of the surge troops coincides with a spike in the number of insider attacks by Afghan forces, who have increasingly turned their weapons on their international counterparts.

Secretary Panetta is in New Zealand in an effort to revive long-suspended defense ties with the island country.

The United States would like to reassert its influence throughout the Asia-Pacific region as China continues to emerge as a military and economic powerhouse.

Panetta arrived in New Zealand after concluding a three-day visit to China, where he was given a rare tour of a Chinese naval base, and was allowed to board a warship and a submarine.