KABUL, Afghanistan -- Democratic presidential candidate Barack Obama pledged steadfast aid to Afghanistan in talks yesterday with its Western-backed leader and vowed to pursue the war on terror "with vigor" if elected, an Afghan official said.

On the second day of an international tour, the Illinois senator and a pair of colleagues held two hours of talks with President Hamid Karzai.

Obama has chided Karzai for not doing more to build confidence in his government, which remains weak after the ouster of the Taliban in 2001.

He made no public comment after the meeting, but he said in a written statement that his main purpose was to see U.S troops, thank them for their service and let them know the United States is proud of them.

"Our message to the Afghan government is this: We want a strong partnership based on 'more for more' -- more resources from the United States and NATO, and more action from the Afghan government to improve the lives of the Afghan people," Obama and Sens. Chuck Hagel, R-Neb., and Jack Reed, D-R.I., said in a joint statement. "We need a sense of urgency and determination.

"We need urgency because the threat from the Taliban and al-Qaida is growing and we must act; we need determination because it will take time to prevail," they said. "But with the right strategy and the resources to back it up, we will get the job done."

The Afghan presidency said Obama's message was positive.

"Sen. Obama conveyed . . . that he is committed to supporting Afghanistan and to continue the war against terrorism with vigor," said Humayun Hamidzada, Karzai's spokesman.

Obama has made Afghanistan a centerpiece of his proposed strategy for dealing with terrorism threats. The Illinois senator has said the war in Afghanistan, where Taliban and al-Qaida-linked militants are resurgent, deserves more troops and more attention as opposed to the conflict in Iraq. Both Obama and his Republican rival for the presidency, Sen. John McCain, advocate sending more forces to the country.

In an interview broadcast yesterday in the United States, Obama described the situation here as "precarious" and "urgent," and said the U.S. should not wait to begin the planning that would be needed to send in more troops. As troops sent to Iraq as part of the buildup of forces there begin to leave, Obama says one to two brigades should be redirected to Afghanistan to bolster the efforts here.

Earlier yesterday, he praised U.S. troops during breakfast with soldiers at Camp Eggers, a heavily fortified military base in the city.

"I want to make sure that everybody back home understands how much pride people take in their work here and how much sacrifice people are making. It is outstanding," he said in footage filmed by the military and obtained by The Associated Press.