BAGHDAD - Vice President Joe Biden pressed Iraqi leaders Friday to do more to foster national reconciliation and offered U.S. assistance in achieving that, as concerns grow that a lack of political progress is fueling violence in Iraq.

Protesters, meanwhile, burned an American flag and chanted anti-U.S. slogans in Baghdad's main Shiite district of Sadr City.

Followers of anti-U.S. Shiite cleric Muqtada al-Sadr hold such demonstrations weekly after Friday prayers, but the rally underscored the challenges facing the United States as it begins drawing down its military forces and losing its dominance in Iraq.

Biden, who was making his first visit to Baghdad since being appointed to oversee the administration's Iraq policy, said he came with a message of continuing support for the country even as the U.S. military pulls back.

"There are still political steps that must be taken and Iraqis must use the political process to resolve their remaining differences and advance their national interest," he said at a joint news conference after meeting with Prime Minister Nouri al-Maliki.

He added that "we stand ready, if asked and if helpful, to help in that process."

The news conference was held in the same hall at al-Maliki's ceremonial residence in which an Iraqi journalist threw his shoes at former President George W. Bush during his last visit to Baghdad in December.

Biden arrived in Baghdad late Thursday for the unannounced visit, two days after all U.S. combat troops were pulled out of Iraq's cities and towns as part of a security agreement that will see all American soldiers out of the country by the end of 2011.

President Barack Obama also has said all combat troops will be gone by the end of August 2010, leaving 30,000 to 50,000 troops in advisory roles.

But Biden's visit and his new position as Obama's point man on Iraq reflect growing concern in the U.S. administration about a recent rise in violence after a series of bombings that killed scores of people.

Al-Maliki, a Shiite, has been criticized for failing to take advantage of security gains to make progress on the political front as divisions deepen before Jan. 30 general elections.

Wearing a tan suit and suede combat boots, Biden held a morning meeting with Gen. Ray Odierno and Ambassador Christopher Hill, America's top soldier and diplomat in Iraq.

The trio made no comments as they emerged from their talks at Odierno's palatial residence at a U.S. military base, but Biden's office said they discussed the withdrawal, the security situation in Iraq, the capabilities of Iraqi forces and political issues.

He then traveled in a 22-vehicle motorcade after a sandstorm prevented him from flying to the walled-off Green Zone, which houses the U.S. Embassy and the Iraqi government headquarters, where he held meetings with al-Maliki and other senior Iraqi officials.

It was his first trip to Iraq as vice president, although he has traveled to the country and met many of its leaders as a senator and said he wanted to re-establish contacts with Iraqi leaders. He plans several trips to the region in the future.

Violence remains at low levels in Iraq compared with previous years, but U.S. and Iraqi officials have warned of more attacks after the city withdrawal deadline.

At least 447 Iraqi civilians were killed in June, double the toll from the previous month, according to an Associated Press tally.

Al-Maliki has called the U.S. withdrawal from cities as a "great victory" and declared June 30 National Sovereignty Day.

On Friday, he expressed gratitude for the U.S. support.

"I have seen very clearly the keen determination from the vice president and his administration to support Iraq ... and a great readiness to give us a lending hand and support when we ask," he said.

Biden also had breakfast with his son, Beau, an Army captain serving in Iraq, in the private room where the vice president spent the night.

Biden planned Saturday to speak at a naturalization ceremony for U.S. troops to mark the Fourth of July, then to travel to the semiautonomous Kurdish region in northern Iraq for meetings with President Jalal Talabani, a Kurd, and Kurdish leader Massoud Barzani.

Associated Press Writer Qassim Abdul-Zahra contributed to this report.