Kerry said he will try and secure greater financial and military backing from the international community for Iraq, in a speech formally accepting the Democratic nomination for president on Thursday.
Although Kerry has made a determined effort to define himself as a clear alternative to Bush at the Democratic National Convention on Thursday, on the key issue of Iraq he held out only the prospect of greater international participation.
"Here is the reality... that won't happen until we have a president who restores America's respect and leadership - so we don't have to go it alone in the world," he said. Kerry voted in the US Senate in 2002 to authorise the invasion of Iraq.
Kerry's calls for greater support from the international community for troops in Iraq coincide with withdrawals from the coalition in Baghdad as nations pull out forces amid a spate of abductions targeting foreigners and unabated armed resistance.
"He's not offering anything new. His position seems to be a carefully calculated to not alienate undecided voters by shying away from a real alternative to Bush's policy"
Carnegie Endowment for International Peace
Washington has seen its occupation force in Iraq reduced by the withdrawal of the Philippines, Spain, the Dominican Republic, Nicaragua and Honduras. The US-led forces in Iraq number 160,000; all but 20,000 are Americans.
Democrats on the left of the party who opposed the Iraq war last year and would like Washington to withdraw troops immediately have muted their arguments at the Democratic National Convention this week in the interest of preserving party unity.
Kerry has argued that Bush deeply alienated traditional US allies by invading Iraq without their support and, without United Nations backing, they are unwilling to bail him out now.
The four-term senator from Massachusetts says he would offer US allies real partnership that would attract practical support from NATO allies and the United Nations.
However, some foreign policy analysts believe Kerry is offering nothing different than Bush on Iraq.
"He's not offering anything new. His position seems to be a carefully calculated to not alienate undecided voters by shying away from a real alternative to Bush's policy," said Joseph Cirincione of the Carnegie Endowment for International Peace.
"I don't think Kerry has come to grips with how great a disaster Iraq really is," he added.
Polls suggest a majority of Americans now believe the decision to invade Iraq last year was a mistake.