Democratic presidential candidate John Kerry (search) on Tuesday demanded a "specific explanation" from President Bush (search) about how his prosecution of the war will lead to a shared goal of a stable Iraq.

"The last several weeks have made it even clearer to Americans than it was before that this mission is not only not accomplished, it is more challenged than perhaps at any time," Kerry said.

Speaking during a fund-raising lunch, Kerry toughened his criticism of Bush, pointing to the president's scheduled news conference Tuesday night against a backdrop of rising violence in Iraq. He said Bush likely will deal with "the instability in Iraq" in the rare prime-time televised meeting with reporters.

"I believe it is important for the president to not just share with all Americans what we all believe. We know we must succeed, we know we are committed to having a stable Iraq," Kerry said. "The president owes Americans a specific explanation of exactly how we are going to achieve that."

The Massachusetts senator said he timed his comments to coincide with the approach of the first anniversary of Bush landing on an aircraft carrier to announce the end to major combat in Iraq (search).

On May 1, 2003, the president donned a flight suit and landed on the USS Abraham Lincoln (search). Speaking under a banner that declared "Mission Accomplished," Bush appeared to be declaring victory in the war.

Kerry said, "Now we know with an incredible collapse of security in Iraq, we know to what degree those words 'mission accomplished' missed the mark and to what degree we remain challenged today."

In addition, Kerry renewed his criticism of what he sees as Bush's unilateral approach to the war.

"As we stand here today, America is carrying virtually the entire burden in Iraq," he said. "I believe that our policies must change."

In a statement, Bush campaign spokesman Steve Schmidt responded: "It's outrageous that Senator Kerry would blame the violence and the attacks made by the insurgents on the administration. Senator Kerry does not seem to understand that it is the terrorists who are to blame for the violence in Iraq."

Kerry planned to focus the week on soaring college costs while touring campuses, but was finding the campaign dominated by unrest in Iraq and the growing violence.

When a questioner pressed him to concede that the United States had made a mistake in Iraq, Kerry said: "I think we've already made it clear, many of us, that the way the president went about this was more than a mistake, in the sense that the president broke promises. ... He promised he would go to war as a last resort. He broke every one of those promises."

With the increasing violence in Iraq, the war has taken a more prominent place in the campaign's debate. Kerry routinely chides Bush for not broadening the effort to include more nations.

"I think this is one of the great failures in judgment about how you take a nation to war," he said.

Kerry, writing in a column in Tuesday's editions of The Washington Post, said the military alone cannot win peace in Iraq and called for "a political strategy that will work."

"Because of the way the White House has run the war, we are left with the United States bearing most of the costs and risks associated with every aspect of the Iraqi transition," Kerry wrote. "We have lost lives, time, momentum and credibility. And we are seeing increasing numbers of Iraqis lashing out at the United States to express their frustration over what the Bush administration has and hasn't done."

Kerry praised the Bush administration for recently asking U.N. representative Lakhdar Brahimi (search) to help develop a formula for an interim Iraqi government. But he said Brahimi's mission will be undermined unless the United States pledges in advance to support any plan he proposes that gains the support of Iraqi leaders.

Kerry said the United States must attract more international troops to serve on the ground in Iraq and urged the government to make the United Nations a full partner in developing Iraq's transition to a new government. He said Bush should also ask NATO (search) to create a new out-of-area operation for Iraq under the lead of a U.S. commander to help the United States get more troops from major powers.

While being critical of Bush's Iraq policy, Kerry took time to raise money. He brought in $1 million at the Providence lunch, and did even better at a big event Tuesday night in Boston, where he raised $4 million for his campaign and another $1 million for the Democratic National Committee.