Democratic presidential nominee John Kerry took his campaign to the airwaves Sunday. In interviews with four American television networks, he talked about the war on terrorism and the Bush administration's credibility abroad.

Senator Kerry says America needs a fresh start, and vows to take a very different approach to foreign policy.

He told CNN's Late Edition that, as president, he would move to bring home U.S. troops from Iraq. He said he would not go into details of an exit plan, because he did not want to negotiate in public. But he stressed, restoring ties strained by the war is a crucial first step.

"I can bring the credibility to the table that allows me a number of negotiating tools that this administration doesn't have available to it," said Mr. Kerry.

The Democratic presidential nominee spoke of the need to rethink U.S. policy and work with allies on North Korea, Africa, arms control and the battle against the disease, HIV-AIDS. During an appearance on Fox News Sunday, he warned the stakes are high.

"The truth is, this president has failed in his conduct of diplomacy," he said.

Mr. Kerry was then asked if President Bush exaggerated the threat from Iraq in order to make the case for war. He said he would not go so far as to publicly accuse the Bush administration of lying, and seemed to chose his words carefully.

"They misled America, whether or not it was intentional or not is up to Americans to decide," he said.

In all, the Democratic nominee recorded interviews with four television networks for their Sunday news interview programs. With his running mate, Senator John Edwards, at his side, he paused from a two-week campaign bus tour that is taking him to states where the race for the White House is already very tight.

Public opinion polls conducted at the close of the Democratic convention show Mr. Kerry got a slight boost from his four days in the political spotlight. Mathew Dowd, an advisor to the Bush-Cheney campaign, told Fox News Sunday the Republicans are not worried.

"I think as soon as the president, which he started to do this weekend, lays out his vision for the future and what he wants to do in the next term on the big issues like the economy and health care and taxes and the war on terror, the American public will respond to that," said Mathew Dowd. "But we have some time to go. It is a tight race and we are looking forward to it."

President Bush returned to the White House Saturday night after a two-day campaign trip. He will be formally nominated by his party when Republicans gather four weeks from now in New York City.