U.S. ranking Senate Republicans on Sunday blasted President Barack Obama's Afghanistan strategy, dismissing the July 2011 deadline as a "political decision" not based on military strategy.

"It was purely a political decision, not one based on facts on the ground, not one based on military strategy," Republican Senator John McCain said on NBC's "Meet the Press," referring to a strategy unveiled by President Obama in December, which called for a buildup of 30,000 troops in Afghanistan and beginning pulling out in July 2011.

"You tell the enemy you're leaving, they will wait," he said. " In wars you declare when you're leaving after you've succeeded."

Republican Senator Lindsey Graham joined McCain in criticizing Obama's Afghan timetable.

"If everybody in Afghanistan believes that we're going to begin to leave in July 2011 no matter what, it's going to be hard to win over people on the fence and that's gotta change, or we're gonna lose," he said on "Fox News Sunday".

Republican Senator Saxby Chambliss said on CNN's "State of the Union" that "it's a huge mistake to even put that deadline out there."

"Because the enemy is watching, and you can rest assured that they are going to be looking to see if we in fact intend to begin pulling out?from July 1 of 2011. And if that remains a hard and firm date then you better believe they are going to sit back and allow us to start pulling out then hit us with their full force," he explained.

Obama's new Afghan strategy did not proceed as smoothly as anticipated. After U.S. and NATO forces having mounted a major push against Taliban in Marja in southern Afghanistan earlier this year, militants there have regained momentum in recent months, forcing the U.S. to postpone major military operations to secure Kandahar, the birthplace of Taliban in Afghanistan.