WASHINGTON, Aug. 23 (Xinhua) -- U.S. Vice President Joe Biden on Monday said he is "confident" that Iraqi leader will form a national unity government as U.S. combat forces pull out of that country.

"I am absolutely confident that Iraq will form a national unity government that will be able to sustain that country," Biden said during a speech given at a U.S. military veteran gathering in Indiana.

The Iraqi sides are at odds with each other and have been unable to form a government months after the March 7 parliamentary elections. Experts have been warning that the political stalemate could be dangerous as U.S. troops leave.

Biden said he personally made it clear to the leading Iraqi politicians that it is time "for them to match the courage of their citizens by completing this process."

Earlier last week, the last full U.S. combat brigade left Iraq. A formal change in mission is set for Sept. 1. There will be about 50,000 non-combat troops in Iraq after that, conducting support and training missions. The last U.S. troops is scheduled to leave Iraq by the end of 2011.

In the same speech, Biden also talked about the war in Afghanistan, saying troops there are making "progress." He said the July 2011 deadline President Barack Obama set for the start of a troop withdrawal does not signal departure, but the beginning of a gradual handover to Afghan security forces.