By Andrew Quinn and Khalid al-Ansary

BAGHDAD (Reuters) - Iraq has a hard road ahead if it is to heal the divisions that spurred six years of bloodshed and achieve lasting peace, U.S. Vice President Joe Biden said during a trip there on Friday.

Biden, who President Barack Obama has asked to take the lead in the White House in coordinating Iraq policy, spent a day in meetings with Iraqi Prime Minister Nuri al-Maliki and officials from across the ethnic and sectarian divide.

U.S. forces pulled out of Iraq's towns and cities this week under the terms of a bilateral security pact that paves the way for a full U.S. withdrawal by 2012, raising concerns Iraq has not made sufficient political progress to prevent more fighting.

"...Iraq has traveled a great distance in the past year, but there is a hard road ahead if Iraq is to find lasting peace and stability. It's not over yet," Biden said.

"There are still political steps that must be taken. Iraqis must use the political process to resolve their remaining differences. We stand ready -- if asked and if helpful -- to help in that process."

Hours before he spoke, supporters of radical Shi'ite cleric Moqtada al-Sadr paraded through a Baghdad slum and chanted anti-American slogans to protest against his visit.

U.S. officials in a later briefing said Biden had used the meetings to underscore to Maliki and the other leaders that progress would depend on Iraqis finding their own solutions.

"It was direct and honest," one official said.

Among those cited were disputes over territory, the integration of pro-government militias into political life and agreeing a balance between central and local government.

"The enemies of Iraq want to again reignite sectarian violence ... They will fail," Biden said.

MIXED RECEPTION

After Friday prayers, hundreds and possibly thousands of residents of Sadr City chanted "down, down USA" and burned U.S. flags in protest against Biden's visit. A smaller demonstration also took place in Kerbala, in the Shi'ite south.

Biden helped author a 2006 plan to split Iraq into self-ruled Sunni, Shi'ite and Kurdish enclaves. That plan angered many Iraqis, and was quietly shelved as violence ebbed.

"Biden has come here to divide Iraq according to his plan," said a message from Sadr read out by one Imam in a mosque.

Iraqi politicians had mixed feelings about Biden's visit.

"The reconciliation issue ... should be activated by Iraqis themselves not by others' recommendations," said Abdul-Kareem al-Samarrai, head of parliament's Accordance Front Sunni bloc.

The sectarian warfare and insurgency unleashed by the 2003 U.S.-led invasion have receded dramatically over the past year, but there continue to be large-scale attacks.

Some Iraqis blame U.S. policies for sowing those divisions.

"We haven't experienced neutrality from the U.S. ... They usually back a party against another," said Usama al-Nujaifi, a lawmaker from former Prime Minister Iyad Allawi's Iraqiya list.

White House officials said Biden would meet U.S. commanders and troops, marking the U.S. July 4 Independence Day holiday.

Earlier, he met for breakfast on Friday with his son Beau Biden, who is serving there with the U.S. military.

This was Biden's second trip to Iraq this year and his first as vice president. President Barack Obama visited Iraq in April.

(Additional reporting by Sattar Rahim; Writing by Tim Cocks and Andrew Quinn; Editing by Richard Balmforth)