Democratic presidential candidate Barack Obama, left, greets U.S. Sgt. Anthony R. Lewis in Afghanistan during a visit to Camp Eggers in Kabul on Sunday. (U.S. Combined Security Transition Command Afghanistan/Associated Press)

U.S. presidential contender Barack Obama met with Afghan President Hamid Karzai on Sunday in Afghanistan before heading for Iraq as part of his weeklong foreign tour.

The Democratic senator from Illinois, along with Republican Sen. Chuck Hagel and Democratic Sen. Jack Reed, spoke with Karzai for two hours and reaffirmed the United States' bipartisan support of Afghanistan.

In an interview with CBS News following their meeting, Obama said, "There's starting to be a growing consensus that it's time for us to withdraw some of our combat troops out of Iraq, deploy them here in Afghanistan, and I think we have to seize that opportunity.

Now is the time for us to do it," Obama said in Kabul.

U.S. commanders have begun withdrawing some troops from Iraq, and Obama argues they should be sent to Afghanistan, which he says is the "central front" in the fight against terrorism.

"I think the situation is getting urgent enough that we have got to start doing something now," he said in the interview.

Obama said he and his colleagues were talking to military and diplomatic leaders as well as Afghan leaders about whether the U.S. has the right strategy and resources to defeat the Taliban and al- Qaeda.

The Afghan government had positive things to say about Obama's comments.

"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.

Democrats and Republicans "are friends of Afghanistan and no matter who wins the U.S. elections, Afghanistan will have a very strong partner in the United States," he said.

Earlier Sunday, Obama also met and praised U.S. troops over breakfast at a heavily fortified base in the capital.

The U.S. senators also met with senior officials in Kuwait on Sunday before flying to Iraq where they are expected to meet with U.S. Gen. David Petraeus and Iraqi Prime Minister Nouri al-Maliki.

Obama's aides provided few details, however, citing security concerns.

With files from the Associated Press