US President George W. Bush and Democratic presidential nominee Senator John Kerry stepped up attacks over each other on Iraq on Friday, one day after their first face-to-face debate that many Americans thought Kerry won.

Bush flew to Pennsylvania and then New Hampshire, two battleground states he lost in 2000, and Kerry campaigned in Florida, a state which decided the election in 2000 after a lengthy vote-recounting and legal maneuvers.

In Allentown, Pennsylvania, Bush seized on Kerry's comments during the debate about his view of the pre-emptive strike. "I'll continue to work with our allies and the international community, but I will never submit America's national security to an international test," he said.

In the debate, Kerry said the United States had the right to take pre-emptive actions to protect the country, but said those action must pass "the global test where your countrymen, your people understand fully why you're doing what you're doing."

Bush also mocked Kerry's promise in the debate that if elected he would call a summit to seek more international help for Iraq. "I've never seen a meeting that would depose a tyrant or bring a terrorist to justice," he said.

Instant polls after Thursday night's debate, which was dominated by Iraq and the war on terrorism, showed that many Americans thought Kerry outdid Bush. But the Bush campaign dismissed the polls, pointing to instant polls after the first debate four years ago Bush had with Al Gore. The polls showed Gorea clear winner.

In Florida, Kerry did not let up his fire. He lashed out at Bush's comments in the debate that Kerry wants to leave Iraq without having the job done.

"Nobody's talking about leaving, nobody's talking about wiltingand wavering. We're talking about winning and getting the job doneright," Kerry said.

Bush and Kerry will have two more debates, on Oct. 8 and Oct. 13. The three debates have the potential to tip the race for the White House as polls showed Bush had only a slight lead over Kerry.