After being courted by John F. Kerry to consider joining the Democratic presidential ticket, Sen. John McCain (R-Ariz.) will join President Bush on Air Force One on Friday and introduce him at a campaign event in Reno, Nev., campaign officials said yesterday.

Bush and McCain have had a frosty relationship ever since competing for the Republican nomination in 2000, and Bush aides have fumed at McCain's occasional barbs in televised interviews during which he was asked repeatedly about the vice presidency. McCain's trip with Bush grew out of a meeting this spring between White House senior adviser Karl Rove and John Weaver, a top adviser to McCain, who became a Democratic consultant after the bitter campaign between Bush and McCain.

Rove and Weaver, who both were GOP strategists in Texas, had a well-publicized falling-out in the late 1980s and have been rivals ever since -- a relationship that was strained further by the 2000 campaign. Weaver described Rove as "gracious" and said the two had "a very honest and very frank discussion and let's just leave it at that."

The meeting represented the beginning of a rapprochement between the two men and in a symbolic sense between the Bush and McCain camps. "There had to be a breaking of the ice and a breaking of the logjam," said one source familiar with the meeting. "What better way for that to occur than to have the two main antagonists in the drama doing it?"

The Bush team's outreach to McCain occurred at the same time Kerry was trying to entice the Arizonan to join him on what some Democrats fantasized could be a unity ticket that could attract moderate Republicans. McCain said yesterday on NBC's "Today" show that Kerry had never formally offered him the job, but he did not dispute that they had discussed it. "I would concede that Senator Kerry and I have had numerous conversations, ranging from his overall well-being and other aspects," McCain said. "But for me to say that we have talked about a specific issue, I just don't think it's appropriate. And I promise you I will not be vice president of the United States."

McCain will join Bush on Friday morning in a hangar at Fort Lewis, Wash., where the president will discuss transformation of the military. McCain then will introduce the president at a rally in the Reno-Sparks Convention Center.

The Bush-Cheney campaign would not discuss the behind-the-scenes drama for the record. An administration official said the joint appearance had been scheduled for at least a few days. Campaign spokesman Scott Stanzel said: "Senator McCain is a respected leader in our party. . . . We are grateful that he will be joining President Bush on Friday to talk about why it's important for President Bush to be reelected for four more years."

McCain is Arizona co-chairman of Bush's campaign, along with Sen. Jon Kyl (R-Ariz.).