Defence Secretary Robert Gates said on Wednesday that US Marines have got the upper hand on the Taliban in Helmand, one of the fiercest battlegrounds in Afghanistan.

"The Marines, since arriving a year ago last summer, have really been in the fight and I think have not just... stopped the momentum of the Taliban but in a lot of places reversed it as well," Gates told members of the 1st Marine Logistics Group at Camp Leatherneck.

"You are making a difference," he told the marines.

A US troop surge ordered by President Barack Obama last December has doubled the number of NATO troops in the southern province of Helmand, the country's largest province and the heartland of the global opium trade.

Gates, who arrived in Afghanistan on Tuesday ahead of a White House strategy review, said the war effort was "on the right track".

His comments were the latest indication that Obama will likely stick to his current strategy in Afghanistan, with nearly 100,000 US troops on the ground.

US and NATO Officials are touting what they call slow but steady progress in the nine-year war against a Taliban-led insurgency.

Major General Richard Mills, the overall commander in Helmand, greeted Gates at the sprawling desert base and told reporters that Afghan forces were assuming an increasingly prominent role in some districts.

"Things are progressing along at a very steady and satisfactory rate," Mills said.

He added that "conditions are set in certain parts of the province right now" for a possible handover to Afghan forces.