Democratic presidential candidate John Kerry (search) promised to be a "veteran's veteran" Tuesday as the White House tried to sour his support among a key constituency by airing a commercial accusing him of rejecting funding for soldiers at war in Iraq.

Kerry warned an audience of veterans that President Bush has misled the country on everything from the war to the economy and had broken promises to veterans needing health care. From the Oval Office on Tuesday, Bush questioned Kerry's own truthfulness by calling for him to identify the world leaders Kerry has said would rather see him as president.

The Massachusetts Democrat later went to Charleston to accept his near-uncontested win in the Illinois primary, which his campaign says gives him the delegates needed to mathematically clinch the nomination. Kerry will claim that prize at the Democratic convention in Boston this summer.

He thanked Illinois voters "for helping us achieve our goal — a nomination marked by unity and not division."

"Together, in the months ahead, we will call on the best in Americans — and stand up for the best in America," Kerry told about several thousand cheering backers. "I say to you tonight: A new day is on the way."

The primary win was one bright spot during a series of tough days for Kerry. He came under a choreographed assault from Republicans from Bush on down after refusing to name the world leaders he says privately support his campaign. At the same time, Bush launched negative campaign ads that seek to define Kerry in harsh terms for the many voters to whom he is still unfamiliar. Both moves have made it difficult for Kerry to get his message out to voters.

In his first visit to West Virginia since becoming the presumptive nominee, Kerry tried to define himself as a war hero. The state, with 203,000 veterans, or 15.4 percent of its adult population, is home to more veterans per capita than all but Alaska, Montana, Nevada and Wyoming. Although solidly Democratic in past elections, West Virginia sided with Bush instead of Al Gore (search) in 2000. Its five electoral votes would be essential in another close election.

"Nothing is more important than telling the American people the truth about the economy, health care, and war and peace," Kerry told veterans in Huntington. "This administration has yet to level with the American people."

In a nod to Mountain State geography, Kerry said, "On issue after issue, this president's misleading misstatements have produced a credibility gap as big as the New River Gorge."

Although Kerry has said he won't break confidences by naming any of the overseas leaders, Bush told reporters, "If you're going to make an accusation in the course of a presidential campaign, you ought to back it up with facts."

For the second day in a row, Vice President Dick Cheney (search) criticized Kerry at a Republican fund-raiser. "We are the ones who get to determine the outcome of this election, not unnamed foreign leaders," Cheney told donors at a benefit for Rep. Bob Beauprez, R-Colo.

In a speech to be delivered Wednesday at the Ronald Reagan Presidential Library (search) in California, Cheney will try to draw a contrast between Kerry and Bush in national security terms. "The American people will have a clear choice in the election of 2004 — at least as clear as any since the election of 1984," Cheney says, according to an advance text of his speech.

Howard Dean (search), Kerry's former rival, said it was "silly" for the Bush administration to suggest Kerry reveal names, "given the proclivity of this administration to threaten those both home and abroad who are candid."

"If I were Senator Kerry I wouldn't name those names because this administration would clearly make their lives difficult," said Dean, a former governor of Vermont.

Joining Kerry in Huntington were seven members of swift boats he commanded in Vietnam, service that won him three Purple Hearts, a Bronze Star and a Silver Star. At the same time, the Bush campaign released a television ad accusing Kerry of being "wrong on defense" by not supporting bills that would have ensured troops had body armor and higher combat pay and given reservists and their families better health care.

"Few votes in Congress are as important as funding our troops at war. Though John Kerry voted in October of 2002 for military action in Iraq, he later voted against funding our soldiers," the ad says.

Kerry labeled the ad "another distortion," arguing that he would have supported funding for the troops if Bush had eased his tax cut to avoid exploding the deficit.

"I'm not going to worry about the misleading," Kerry said. "I'm going to keep pounding away at the truth. We're going to build an army of truth-tellers."

Bush campaign spokesman Steve Schmidt rejected Kerry's argument, charging Kerry with abandoning troops.

"While he falsely attacks the president over veteran's funding, John Kerry authorized our troops to liberate Iraq and then voted against funding for body armor, increased combat pay and health care to support them," Schmidt said.

By winning the Illinois primary, Kerry boosted his delegate total to at least 2,252, well past the 2,162 needed to secure the nomination at the Democratic convention in July.

Kerry was returning to Washington on Wednesday for a speech before flying to Ketchum, Idaho, to begin a five-day vacation.