KANDAHAR, Afghanistan - It's business as usual for Canadian troops in Afghanistan as U.S. Gen. David Petraeus takes command of coalition forces in the country.

Petraeus arrived Friday in Kabul, where the Afghan government is being helped by up to 150,000 international troops in the fight against the Taliban insurgency.

An influx of U.S. troops has brought an additional 20,000 Americans to Afghanistan, with more expected by the end of the summer.

Petraeus replaces Gen. Stanley McChrystal, who resigned when he was called to Washington to explain disparaging remarks he made in Rolling Stone magazine about officials in U.S. President Barack Obama's administration.

Canadian Brig.-Gen. Jonathan Vance, commander of Task Force Kandahar, said he expects Petraeus to put his mark on the war effort but the overall direction would not change much.

"Gen. Petraeus is certainly an expert in all things to do with counterinsurgency and the wars in Iraq and now in Afghanistan," Vance said in a recent interview.

"There's no feeling of discomfort," Vance said. "I trust him and he will do a great job and, like any commander, will bring his own brand of leadership and expertise to bear and we look forward to that."

"Every commander will put his mark on the mission, but I think what we're dealing with here is a fairly well developed and doctrinally sound methodology that suits the broad policies that are in place," Vance said.

Canada has about 2,800 troops involved in the Afghanistan mission. Most of them are in Kandahar, which has been divided into three battle zones. The Canadians focus their attention on the Panjwaii and Dand districts, traditional haunts of the Taliban.

While normal operations will continue to clear out nests of Taliban, the goal is to tackle the insurgents in their strongholds while improving local goverance and providing development assistance.

"As the insurgency changes, so do we; as government changes and becomes more capable, so do we," Vance said. "So I would expect the continuity will be very evident to all of us here as we carry on this summer."

Petraeus, credited with turning around the Iraq war after the height of sectarian violence there in 2006, became chief of U.S. Central Command prior to his new appointment. He has made it clear that he expects fighting with the Taliban to intensify over the summer as more troops bring more pressure.

Vance said the biggest challenge will come from foreign fighters who come to Afghanistan from Pakistan and other areas to bolster the insurgency in the summer fighting season.

"We have to get far more robust because there are greater numbers willing to fight. We have to start using more offensive operations to protect that which is starting to gain some traction," he said.

"There's a recognition that they're trying harder," he said, as the insurgents face tougher action from the coalition.