Gen. David Petraeus, U.S. President Barack Obama's pick as the new commander in Afghanistan, said on Tuesday that fighting in the country could intensify in coming months and he supports the timetable of starting withdrawals in July 2011.

U.S. General David Petraeus testifies before the Senate Armed Services Committee for a confirmation hearing to become commander of the International Security Assistance Force and commander of the U.S. Forces in Afghanistan on Capitol Hill in Washington June 29, 2010. [Zhang Jun/Xinhua]

Petraeus appeared before the Senate Armed Services Committee, testifying at a hearing on his confirmation as the new commander of U.S. and NATO forces in Afghanistan.

There were signs of progress in terms of U.S.-led counterinsurgency effort in Afghanistan and fighting in the country could intensify in coming months, said the general, who was tapped by Obama last week to succeed the loose-lip Gen. Stanley McChrystal.

"My sense is that the tough fighting will continue; indeed, it may get more intense in the next few months," he said. "As we take away the enemy's safe havens and reduce the enemy's freedom of action, the insurgents will fight back."

Petraeus also restated his support for starting withdrawal of U.S. troops in Afghanistan in July 2011, a major part of Obama's new Afghan strategy outlined in December, while emphasized that it would be based on security conditions on the ground.

The general promised to forge "unity of effort" with his civilian counterparts, saying that he will "seek to contribute to such teamwork and to unity of effort among all participants."

His predecessor, McChrystal, failed to get on well with U.S. diplomatic team in Afghanistan and was ousted after making contemptuous remarks of senior administration officials.

Petraeus is expected to be heavily questioned by lawmakers on whether he would pursue the same doctrine as his predecessor to put strict limits on firepower to protect the lives of civilians, which critics say put U.S. troops at unnecessary risk.

"I am keenly aware of concerns by some of our troopers on the ground about the application of our rules of engagement and the tactical directive. They should know that I will look very hard at this issue," Petraeus said in his testimony.