The president said his administration had completed a review of its Afghan strategy, and would work to increase the size of the Afghan army from 32,000 troops to 70,000 by the end of next year, and to bring in additional allied troops to support the fledgling army.

“When there is a need, when the commanders on the ground say to our respective countries, ‘We need additional help,’ our NATO countries must provide it in order to be successful in the mission,” Mr. Bush said.

He promised to build new roads that would help spur economic development, to battle an increase in the opium trade and to try to forge better ties between Afghanistan and its neighbor, Pakistan.

At the same time, Mr. Bush pledged to work with President Pervez Musharraf of Pakistan to root out Taliban and Qaeda fighters who hide in that country’s remote mountainous regions — a situation he described as “wilder than the Wild West.” And, echoing his lament that 2006 was a difficult and disappointing year for Iraq, the president said the same had been true in Afghanistan.

Some critics of the administration’s handling of Afghanistan said Mr. Bush was still understating the difficulties there.

“We underfinanced, undermanned and under-resourced the war in Afghanistan for the last four years, and now we face a serious threat that the Taliban will succeed in destabilizing the country enough in 2007 to make the Karzai government collapse at some point,” said Bruce Riedel, a scholar at the Saban Center for Middle East Studies at the Brookings Institution, a liberal-leaning research organization in Washington. He called the speech “a long overdue recognition that we need to do a lot more.”

Both Mr. Riedel and Rick Barton, an expert in Afghanistan reconstruction at the Center for Strategic and International Studies in Washington, said Mr. Bush’s new strategy did not do enough to promote security and economic development. Mr. Barton, who published a report in 2005 measuring progress in Afghanistan in that year, is about to publish another, and said the situation has turned measurably worse since his first study.