BREAKING: Trump to announce VP pick by July 15: report

"By this time next Monday, we will know who President Trump has selected as his running mate for the 2024 election," Miller told Fox & Friends. "It could happen any time this week. Could happen literally right up until the first day of the convention. Miller also said that he didn't believe that Biden and his VP Kamala Harris would even be on the Democrat ticket come November. The DNC comes a few weeks after the RNC and will be staged in Chicago.

"I look ahead as a campaign strategist to what does that vice presidential debate look like," Miller said. "We don't know if that's going to be Kamala, or maybe they swap her out for someone who's even more liberal, more extreme, although that might be tough to do," Miller said.

Trump has previously said that he knows who he will choose, and that he intends to make his announcement "right around the convention, maybe a little before."

"It's almost an embarrassment of riches that there are so many good people," Miller said. "And what President Trump has said is that whoever he does pick needs to be able to step in and do the job on day one." He confirmed that Trump has many "great choices" and that there are many more names on the short list.

"President Trump has discussed even more names than that," Mille said when asked about the names on the shortlist. "What we don't know is who President Trump and his running mate will be running against," Miller said. "Ultimately, with all the talk this morning about Joe Biden and whether or not he can hang on in the presidential spot."