WASHINGTON - A U.S.-led international coalition in Afghanistan may "turn a corner" in its decade-long war against Taliban as early as at the end of the year, U.S. Defense Secretary Robert Gates has said. "My own view is that this year is a critical year," the Pentagon chief told journalists in Washington on Thursday.

Coalition forces have "driven the Taliban out of areas they have controlled for years, including their heartland," he said. "They clearly intend to try and take that back. If we can prevent them... and we can continue to expand the security bubble, I think it's possible that by the end of this year we will have turned a corner just because of the Taliban being driven out, and, more importantly, kept out," Gates said.

The U.S.-led coalition has been fighting Taliban militants in Afghanistan since 2001, but attacks on both foreign and Afghan troops, police and civilians are still frequent, with most of them taking place in volatile southern regions. Gates said "we are all expecting an increase in the level of violence and activity beginning in a few weeks."

U.S. troops are scheduled to begin withdrawing from Afghanistan in July 2011, followed by other contingents involved in the International Security Assistance Force (ISAF). Responsibility for security will be gradually handed over to Afghan military and security forces. (Agencies)