Republican presidential nominee-in-waiting John McCain stayed mum about his a running mate deliberations Thursday and one top prospect abruptly canceled numerous public appearances.

Without explanation, Minnesota Gov. Tim Pawlenty called off an Associated Press interview at the last minute, as well as other media interviews in Denver, site of the Democratic National Convention.

Others believed to be in contention for the No. 2 slot on the GOP ticket included former Massachusetts Gov. Mitt Romney, who was meeting with donors throughout California, and Democrat-turned-independent Sen. Joe Lieberman of Connecticut, who was vacationing on Long Island.

Former Pennsylvania Gov. Tom Ridge, too, was still a possibility, as was the idea that McCain would choose a dark horse from any number of names that have circulated.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP’s earlier story is below.

DENVER (AP) _ Looking toward his turn in the spotlight, Republican presidential nominee-in-waiting John McCain sought to siphon attention from Democrat Barack Obama’s show in Denver by playing coy about his pick for vice president.

McCain is widely expected to name his running mate in the coming days, perhaps as early as Thursday night or Friday, but said in an interview aired Thursday morning that he still hadn’t made up his mind. Far from quieting speculation, this only fueled it.

The hope in the McCain camp _ with both the eventual pick and the effort to keep buzz alive beforehand _ is to curb any uptick in polling that Obama might get from his convention and to create momentum heading into the gathering of GOP delegates for McCain next week in St. Paul, Minn.

Republicans with ties to McCain’s campaign said final deliberations this week were focused on former Massachusetts Gov. Mitt Romney, Minnesota Gov. Tim Pawlenty, and Democrat-turned-independent Sen. Joe Lieberman of Connecticut.

Former Pennsylvania Gov. Tom Ridge, too, was still a possibility, as was the idea that McCain would choose a dark horse from any number of names that have circulated. One of those, former Secretary of State Colin Powell, was quickly taken out of contention by a spokeswoman. Peggy Cifrino said Powell “is not interested in serving on either ticket.”

Pawlenty, in Denver to criticize Democrats on McCain’s behalf, canceled without explanation an afternoon roundtable interview with The Associated Press as well as other media interviews. Questioned about the vice presidential selection earlier, Pawlenty would only say that he is to be in Minnesota on Friday for the state fair. He had cautioned during a series of morning TV interviews that while speculation might be fun, “most of it turns out to be inaccurate.”

Romney, who had played the GOP attack-dog role earlier in the week at the Democratic convention and has been meeting with donors in California, left his beachfront San Diego home Thursday morning with an overnight bag. His son, Matt, said Romney was headed to an unspecified location in the state. Asked about being vice president, the elder Romney said: “I don’t have anything for you right now.”

Ridge was at his suburban Washington, D.C., home. Asked by an AP photographer as he took out the trash if he had any travel plans for the day, Ridge smiled and said he didn’t.

One Lieberman aide said there has been no indication he is the choice. For instance, no staff have been called to go to New York’s Long Island where he is vacationing.

For months, McCain’s vice presidential search process has been kept closely held by a small group of his advisers. But details have been trickling out this week. This includes word from two Republicans that McCain met with his senior advisers in Arizona on Wednesday to discuss the pick, conflicting information about whether or not he had settled on a choice, and the campaign’s announcement it would air a TV ad in battleground states around when Obama will be giving his prime-time acceptance speech. A spokeswoman said McCain would be shown speaking directly to camera with a message aimed at Obama but would not disclose the content.

The strategy was all but certainly employed to inject the Republican’s name into news coverage dominated by Obama.

McCain said in the interview with KDKA NewsRadio in Pittsburgh that was taped Wednesday: “I haven’t decided yet so I can’t tell you.”

McCain, who spoke with the radio station from his home in Arizona, has told people that he would make no final decision until after he talks with his wife, Cindy. She has been in the country of Georgia this week and had been expected to return late Wednesday.

McCain and his No. 2 are expected to appear together for the first time at one or more rallies planned for Ohio, Pennsylvania and Missouri in the run-up to Monday’s convention kickoff.

In the radio interview, McCain said that he was bringing along to the Pennsylvania event on Saturday both Ridge and Romney. But he cautioned against assuming that meant either one would be the pick.

However, McCain talked glowingly of Ridge, a longtime friend who has been a frequent presence at his side during the campaign and who, in a break from McCain, backs abortion rights. “He’s a great American and a great and dear friend and I rely on him and I have for many years,” McCain said.

Asked to hint which way he is leaning, McCain turned _ as he has for days _ to a joke, saying it would be actor Wilford Brimley. “He’s a former Marine and great guy and he’s older than I am, so that might work,” said the four-term Arizona senator, who turns 72 on Friday.

Inside GOP circles Thursday, though, speculation swirled around Lieberman. It was fueled by reports that McCain’s advisers had asked for additional detailed information from Lieberman, by McCain’s close friendship with the 2000 Democratic vice presidential nominee, and by word that Republican operatives had been told to prepare for the possibility of an “unconventional” choice. Lieberman supports the Iraq war but breaks with Republicans on most issues, notably abortion rights.

GOP strategist Karl Rove late last week encouraged Lieberman to withdraw his name from vice presidential consideration, but Lieberman rejected the suggestion, according to a person familiar with the phone call, who requested anonymity because he was not authorized to speak publicly about it. Rove, through a spokeswoman, denied he made the call.

There’s been talk among Republican insiders that, should McCain choose Lieberman, he may well declare in his vice presidential speech or his nomination acceptance speech that he will serve only a single four-year term. GOP operatives say that, combined with putting Lieberman on the ticket, could reinforce McCain’s claim that he would put the country above partisan politics. It also could address concerns about his age.

Conversely, a Lieberman pick would be all but certain to ignite a revolt on the GOP’s right flank. Hard-core Republicans likely would question why someone who doesn’t adhere to GOP orthodoxy would be a heartbeat from the presidency and the prohibitive Republican favorite going into the 2012 election. That would also raise lame-duck questions and literally touch off the 2012 race as soon as this election ends _ if not sooner.

A pick of Lieberman could also create chaos in the Senate, where the Democratic majority depends on support from the Connecticut senator. If Lieberman decided he was no longer siding with Democrats for organizational purposes, the result would be a 50-50 tie that Vice President Dick Cheney could then break in favor of Republicans.

___

Associated Press writers Glen Johnson in Boston and Andrew Miga and photographer Scott Applewhite in Washington contributed to this story.