A U.S. official told CNN Saturday that the Illinois senator is planning on meeting with Karzai on Sunday before beginning his tour of the Middle East and Europe.

CNN said Obama, who arrived in Afghanistan Saturday, had never visited the Asian country before.

The details of Obama's trip have been kept largely secret because of security concerns. A pool report released by his campaign said he left Andrews Air Force base near Washington on Thursday.

In addition to stops in Afghanistan and Iraq, Obama is also set to visit European capitals during his tour, which is intended to counter criticism he lacks foreign policy expertise.

The New York Times said Obama proposed in a speech this week that the United States should send nearly 10,000 more troops to Afghanistan to counter tough resistance from Taliban militants.