Suspense builds around Trump's vice presidential pick

Former President Donald Trump is expected to announce his running mate in the coming days, with the focus zeroing in on Sens. Marco Rubio, J.D. Vance and North Dakota Gov. Doug Burgum.

Trump has been teasing his vice presidential pick for months and whoever he chooses will speak at the Republican National Convention next week.

On the "The Clay Travis & Buck Sexton Show" on Friday, Trump said he would like to announce his vice presidential pick during the RNC next week or slightly before that -- suggesting Monday as a possibility.

"I'd love to do it during the convention, which would be, you know, or just slightly before the convention, like Monday," Trump said. "I'd love to do it on Tuesday or Wednesday, actually, but for a lot of complex reasons that you people understand, pretty much don't do that."

During the interview, he compared the selection of his running mate to a "highly sophisticated version of The Apprentice."

His senior adviser, Jason Miller, said earlier this week that Trump could announce his choice "any time this week" as the RNC approaches. All eyes will be on Trump as he hosts a rally in Butler, Pennsylvania, on Saturday -- just days before the RNC kicks off.

As his supporters and others in the political world await Trump's announcement of his running mate, his top contenders continue their usual activities, patiently waiting for the former president's call.

Both Rubio and Vance were in Washington, D.C., this week -- on Capitol Hill. ABC News asked Vance if he had talked to the president about serving as vice president. He said no.

After Trump's debate with President Joe Biden, Burgum avoided questions about being Trump's running mate. Asked if he were still actively being vetted for the job, Burgum ignored the question, responding, "Tonight's all about President Trump."

Before his return to Washington, Rubio took the stage at Trump's rally in Doral, Florida, on Tuesday evening, lauding Trump for his administration's accomplishments.

During the rally, Rubio said that Biden wanted the 2024 campaign to focus on anything other than the comparison between Biden and Trump.

"Well, that's what this campaign is. That's what this campaign is all about. That's why he was the 45th President of the United States, and that's why Donald Trump will be the 47th President of the United States of America," Rubio said.

Trump's pick for his No. 2 comes at a critical time in the campaign cycle as a growing number of Democrats call for Biden to step aside as the party's nominee and rally behind Vice President Kamala Harris.

Over the past few days, Trump and his vice presidential contenders have targeted Harris as talk grows about wanting her to challenge the former president in November.

"Despite all the Democrat panic this week, the truth is it doesn't matter who they nominate because we are going to beat any one of them in thundering landslides," Trump said on Tuesday night in Doral.

On Tuesday night, Vance accused Harris of being part of a cover-up on Biden's fitness for office.

"This is a person who, for four years, has saddled the United States with a president who can't do the job, and she did it all for political power," Vance said about Harris on Fox News. "She knew that whether it was now or four years from now, she would be the person who stood to inherit the presidency."

ABC News' Soorin Kim, Lalee Ibssa and Kelsey Walsh contributed to this report.