John F. Kerry said Tuesday that President Bush lacks the credibility to lead the world in the war on terrorism, charging that Bush had missed an opportunity to rally support for the U.S. mission in Iraq by failing to level with world leaders at the United Nations about conditions on the ground in that country.

The Democratic presidential nominee used his first news conference in more than a month to respond to Bush's morning speech to the U.N. General Assembly as he continued his effort to shift the debate over Iraq from questions about his own positions to a critique of Bush's policies.

"I believe the president missed an opportunity of enormous importance for our nation and for the world," Kerry told reporters in Jacksonville. "He does not have the credibility to lead the world. And he did not and will not offer the leadership in order to do what we need to do to protect our troops, to be successful and win the war on terror in an effective way."

Later, at a rally in Orlando, Kerry ripped Bush for saying earlier in the day that the CIA was "just guessing" in a July national intelligence estimate that painted a gloomy portrait of Iraq's future. "Does that give you confidence that this president knows what he's talking about?" Kerry asked. "The CIA was just guessing! This president ought to be turning that CIA over, upside down, if that's all they were doing."

A day after delivering his broadest indictment to date of Bush's Iraq policies, Kerry also sought to deflect criticism from the president that the Massachusetts senator's speech Monday marked another shift in positions and that Kerry believes that the world would be better off if Saddam Hussein had not been deposed.

"What I have always said is that the world is better off without Saddam Hussein," Kerry said. "The question is how you do it. And what the president needs to begin to do is address the realities of Iraq. The president keeps wanting to debate fiction or hypotheticals rather than debate the reality of what's on the ground."

Returning to the subject later, he said Bush was irresponsible in failing to let the U.N. weapons inspection process play out long enough to show that Hussein did not have weapons of mass destruction, a revelation that Kerry said probably would have led to Hussein's toppling.

"If you don't have weapons of mass destruction, believe me, Saddam Hussein is a very different person," Kerry said. "That's what kept him in power. And I believe Saddam Hussein would not be in power. This president avoided approaching this in responsible ways, and it's a tragedy."

Kerry did not directly answer a question about whether he agrees with U.N. Secretary General Kofi Annan, who called the Iraq war illegal. "I don't know what the law or legalities are," Kerry said. But he said that having the U.N. leader at odds with the United States over such a question makes Bush's hopes of winning international support even more problematic.

Kerry argued that Bush's policies need a dramatic overhaul to prevent Iraq from spiraling out of control, and he said Bush has tried to deny that reality. "This is his job," he said. "He's the president, and Iraq is becoming more and more of a mess every day."

Kerry was questioned repeatedly about some of his past positions on Iraq, particularly his vote for the 2002 resolution, widely seen as authorizing Bush to go to war unilaterally, given his position now that he would not have gone to war.

"The vote for authorization is interpreted by a lot of people as a vote to go to war," he said. "But if you read it, and if you think about what it gave the president, it gave the president what he said: America will speak with one voice. Those are the words of the president."

Kerry has also defended that vote by saying he believed that any president should have been given such authority under the circumstances. But in 1991, he voted against the resolution authorizing President George H.W. Bush to go to war to eject Iraq from Kuwait. He said Tuesday he opposed that resolution because the United States was so divided.

Later, Kerry steered the discussion back to Bush. "The president wants to shift the topic, and I'm not going to let him shift the topic. This is about President Bush and his decisions and his choices and his unwillingness, as I said in my speech yesterday, to live in a world of reality."

Kerry's news conference came on his first trip to Florida in a month. He was kept out of the state that decided the 2000 election by a succession of hurricanes that have ripped up property across the state.

After his news conference, Kerry hosted a town hall meeting on health care and later met up with running mate John Edwards for the rally.

On health care, Kerry said Bush has no plan to expand coverage. He responded to criticism from the president that his own plan would mean a government takeover of the health care system. "It is not a government plan," he said. "It allows every American to choose their doctor, every American to choose their plan. In fact, it provides a broader choice for health care than you have today. And there's no new bureaucracy; it cleans up bureaucracy and gets rid of waste."

Edwards began his day in Ohio with his sharpest criticism yet of Bush's economic policies, calling them "the most radical and dangerous economic agenda to hit our shores since socialism a century ago."

"Just like socialism, it corrupts the very nature of our democracy and our free enterprise tradition," Edwards told a group of business leaders in Cleveland. "It is not a plan to grow the American economy. It is a plan to corrupt the American economy and to shrink the winner's circle."

Edwards said a Kerry administration would roll back tax cuts for the wealthiest Americans, arguing that Bush has a vision that "honors wealth and privilege rather than work and responsibility."

Edwards's speech reflected a desire by the campaign to attack Bush on two fronts simultaneously, and not to let Kerry's focus on Iraq overshadow economic issues, Edwards aides said.

Snyder is traveling with Edwards.

Democratic presidential nominee John F. Kerry and running mate John Edwards campaign at a health care rally in Orlando. Kerry said President Bush has no plan to expand coverage.