LONDON - Gordon Brown launched his campaign to become Britain's next prime minister on Friday, pledging to learn from the mistakes of the Iraq war while honoring "our obligations to the Iraqi people." Brown, who faces no serious opposition after waiting more than a decade for his chance to lead the country, said there needed to be a stronger emphasis on political reconciliation and economic development in Iraq.

"And obviously we've got to more to win the battle of hearts and minds against al-Qaida terrorism."

Prime Minister Tony Blair, who announced he would resign June 27, officially endorsed Brown on Friday. As Treasury chief, Brown is credited with much of Britain's recent economic boom.

"I want to lead a government humble enough to know its place," Brown said, pledging to win back voters disenchanted after a decade of Labour Party rule.

The question is whether Brown will shift Britain's role in the Iraq war, which has divided Britain.

President Bush has called Brown a thinker and easy to talk to. Brown has been more reserved in his comments about the American president, whose alliance with Blair lost the Labour Party votes.

"I accept that mistakes have been made," Brown said, adding that he will soon visit Iraq and other nations.

"We will keep our obligations to the Iraqi people. These are obligations that are part of U.N. resolution, they are in support of a democracy," he said. "I do think that over the next few months the emphasis will shift."

Secretary of State Condoleezza Rice said Brown was aware of the dangers surrounding failure in Iraq.

"The bonds with Prime Minister Blair have been forged through some of the most difficult times, through the time of 9/11, through the time of the attacks on London, through Afghanistan and Iraq and Northern Ireland, and those are bonds of friendship that come from having been through some of the toughest circumstances," Rice told the British Broadcasting Corp.

"But Britain and America will always be friends and I know that we will work very, very well with Gordon Brown when he becomes prime minister."

Jack Straw, former Foreign Secretary, said Brown would respect the alliance with the United States.

"Gordon Brown's affection and understanding of America goes back decades. And he takes the same view as Tony Blair does, which is that Britain's security fundamentally depends on the alliance with the United States and the union with Europe."

The Iraq war severely dented Labor's popularity. Blair's close alliance with President Bush was unpopular at home, there were mass marches in Britain opposing the U.S.-led invasion before it began, and the government's claims that Saddam Hussein was building an arsenal of weapons of mass destruction proved false.

For more than a year, Labour has consistently trailed in opinion polls behind a Conservative Party revived by its new leader, David Cameron.

In local and regional elections earlier this month, Labour lost hundreds of seats in city and county councils, and was beaten into second place in the Scottish Parliament elections by the Scottish National Party, which advocates independence.

Blair announced in February that his government ¡ª the top U.S. ally in the Iraq war ¡ª will reduce its troop level by 1,600 to about 5,500 by spring, but will retain a presence in southern Iraq until at least 2008. A total of 148 British soldiers have died since the 2003 invasion.