(adds Hutchison comment, other details)
By Steve Holland
DENVER Aug 28 A top contender to be Republican John McCain's vice presidential running mate abruptly canceled appointments in Denver on Thursday but it was unclear whether he was McCain's choice.
Minnesota Gov. Tim Pawlenty, in Denver to help provide counterattacks against the Democratic Party convention, canceled participation in a news conference and other appearances, a Republican official said.
It was unclear whether the cancellation had any significance to McCain's vice presidential search.
Pawlenty, 47, was believed to have been on McCain's short list for vice presidential running mates, a list that also included former Massachusetts Gov. Mitt Romney, who lost to McCain in the primary battle, and independent Democratic Sen. Joe Lieberman of Connecticut.
A Republican official said McCain has made up his mind on his No. 2 and was expected to appear with his running mate at a rally on Friday in Dayton, Ohio.
As is traditional, his choice has been a closely guarded secret among a small group of McCain's inner circle.
McCain ignored shouted questions about whether he had made up his mind as he boarded a plane in Phoenix bound for Dayton.
A Friday announcement would be aimed at diverting attention from the Democratic convention in Denver, which ends with a speech by Sen. Barack Obama on Thursday night meant to fire up his effort to win the Nov. 4 election.
Texas Republican Sen. Kay Bailey Hutchinson, whose name has been mentioned frequently in the news media in the past few days as a possibility, told the Fox News Channel that she was not McCain's choice and had not wanted to be considered.
"I have no airline reservations to Ohio," she said.
Asked about Pawlenty, Hutchison said: "I think he is on everyone's short list, you never can tell. My guess is Mitt Romney."
McCain is preparing to accept his party's nomination for president at the Republican convention in St. Paul, Minnesota, next week.
He and his campaign have worked hard to remain in the public eye during the Democratic convention.
As Obama prepared to deliver a speech at a Denver football stadium accepting his party's nomination, McCain issued a television ad congratulating his him.
"Sen. Obama, this is truly a good day for America," McCain said in the ad. "Too often the achievements of our opponents go unnoticed. So I wanted to stop and say, congratulations."
He added: "Tomorrow, we'll be back at it. But tonight Senator, job well done." (Additional reporting by Tim Ryan)