PORTLAND, Ore. (Reuters) - Democratic White House hopeful John Kerry, who has barely mentioned Iraq on the campaign trail this week, said on Monday he wanted to give President Bush "some space to get things done."

"I'm trying not to talk about it in politics," he told reporters aboard his campaign plane en route from Topeka, Kansas, to Portland for a rally with Howard Dean, a former rival for the Democratic presidential nomination.

"I want to give the president some space to get things done and see what happens," Kerry said. "I wish the president would lead. He needs to lead, lives are at stake. He needs to be really bold."

Kerry called for the resignation of Defense Secretary Donald Rumsfeld almost two weeks ago over what he called "miscalculations" on Iraq compounded by a lack of command and control that created the culture for abuse at a U.S.-run Iraqi prison. He also demanded that Bush, as commander in chief, take full responsibility.

Last Friday, after privately viewing photographs of maltreatment at the Abu Ghraib jail, he criticized the Bush administration for "indifference" to the Geneva Conventions and other standards.

But since then, the senator from Massachusetts has turned his attention -- at least publicly -- away from the daily drumbeat of bad news from Iraq, including the assassination on Monday of the head of the Iraqi Governing Council.

"I think it's terrible," he said, but declined to speculate on how he thought the assassination might affect the Bush administration's plan to handover sovereignty to the Iraqis on June 30.

At a rally in Portland, where Dean proved he could still draw huge and enthusiastic crowds, Kerry spoke of Iraq in general terms, urging that its reconstruction be internationalized and denouncing a war of choice rather than necessity, all without mentioning the president by name.

WORKING WITH OTHER COUNTRIES

"We cannot possibly prevail in Iraq if we give up our values in the process," he said. "Our nation is viewed by people all over the world as much more than the name of a country ... we are an idea, a brilliant idea.

"But we deserve to have leadership that understands what every president of the last century understood -- working with other countries, instead of going unilaterally, is not a sign of weakness, it is a sign of strength."

Dean, who vehemently opposed the Iraq war -- unlike Kerry who voted for the congressional resolution authorizing the U.S.-led invasion of Iraq -- was not so kind to Bush.

After praising Kerry's heroism as a decorated Vietnam War veteran, Dean told about 4,000 boisterous supporters crammed into a downtown city square, "I can't wait for a commander in chief who actually served abroad. There's a lot of talk in this election about patriotism ... I haven't heard from anybody on the other side who spent a day of their life overseas."

Bush served in the Texas Air National Guard during the Vietnam War and Vice President Dick Cheney received five draft deferments.

Earlier on Monday, Kerry marked the 50th anniversary of the landmark Supreme Court Brown v. Board of Education decision ending segregation in public schools by warning about forces in the United States who sought "to see it undone."

Bush campaign spokesman Steve Schmidt accused Kerry of politicizing the occasion with "factually inaccurate attacks."