WASHINGTON — President Barack Obama's drawn-out decision-making on Afghanistan is sending messages. To the Afghan government: Clean up your act. To the Pentagon: I'm no rubber stamp. To the American public: More troops can't be the sole answer.

Obama has been accused by some Republicans of "dithering" about whether to send more troops and deepen U.S. involvement in an increasingly unpopular war.

The slow process also has left him open to critics who recall his pronouncement in March, after developing what he called a "stronger, smarter and comprehensive" Afghan war strategy, that the situation there was "increasingly perilous." He ordered more troops to battle then, with little discernible result so far.

This time, he's making it clear he won't be rushed. Or pushed. And the way the messages he's sending play out could help determine whether the war effort is sustainable in the long run.

Defense Secretary Robert Gates told reporters Thursday that the president was nearing a final decision, and he referred to one of the central questions Obama and his advisers have wrestled with for weeks.

"How do we signal resolve and at the same time signal to the Afghans and the American people that this isn't an open-ended commitment?"

At a White House war council meeting Wednesday, Obama rejected the four Afghan war options put before him and asked for revisions that combine the best elements of the proposals, Gates said. The changes could alter the dynamic of both how many additional troops are sent to Afghanistan and their time in the war zone.

Obama is not expected to decide the Afghan matter until after he returns from Asia late next week.

White House press secretary Robert Gibbs told reporters traveling with Obama on Thursday on the first leg of his Asia trip that the president wanted more study of the options to ensure there's a real exit strategy, including benchmarks for success.

"It's important to fully examine not just how we're going to get folks in but how we're going to get folks out," Gibbs said.

Obama himself injected another variable on his way to Asia on Thursday. He told troops at Elmendorf Air Force Base in Alaska that he won't send troops into harm's way without the support they need to succeed — including "public support back home." Polling shows most Americans oppose a troop increase.

Meanwhile, Richard C. Holbrooke, Obama's special representative for Afghanistan and Pakistan, left late Wednesday for consultations with officials in Germany, France and Russia. State Department spokesman Ian C. Kelly said Holbrooke would then attend President Hamid Karzai's inauguration in Kabul.