By ANNE GEARAN and LARA JAKES

Associated Press

WASHINGTON — President Barack Obama won’t walk away from the flagging war in Afghanistan, the White House declared Monday as Obama faced tough decisions — and intense administration debate — over choices that could help define his presidency in his first year as commander in chief.

The fierce Taliban attack that killed eight American soldiers over the weekend added to the pressure. The assault overwhelmed a remote U.S. outpost where American forces have been stretched thin in battling insurgents, underscoring an appeal from Obama’s top Afghanistan commander for as many as 40,000 additional forces — and at the same time reminding the nation of the costs of war.

Obama’s defense secretary, Robert Gates, appealed for calm — and for time for the president to come to a decision.

Obama may take weeks to decide whether to add more troops, but the idea of pulling out isn’t on the table as a way to deal with a war nearing its ninth year, White House press secretary Robert Gibbs said.

“I don’t think we have the option to leave. That’s quite clear,” Gibbs said.

The question of whether to further escalate the conflict after adding 21,000 U.S. troops earlier this year is a major decision facing Obama and senior administration policy advisers this week.

Obama also invited a bipartisan group of congressional leaders to the White House on Tuesday to confer about the war. And Obama will meet twice this week with his top national security advisers.

Divided on Afghanistan, Congress takes up a massive defense spending bill this week even before the president settles on a direction for the war.

Defense Secretary Gates said Monday that Obama needs elbow room to make strategy decisions about the war and appealed for calm as the internal Obama White House debate goes increasingly public.

Gates has not said whether he supports the recommendation of the top commander in Afghanistan to expand the number of U.S. forces by as much as nearly 60 percent. He is holding that request in his desk drawer while Obama sorts through competing recommendations and theories.

“I believe that the decisions that the president will make for the next stage of the Afghanistan campaign will be among the most important of his presidency,” Gates said.