Donald Trump drops hints on VP pick, says he has narrowed field down to 'four or five' candidates

In his first interview since the end of Republican primary season, Donald Trump discussed the progress he's made in his search for a running mate.

The presumptive Republican nominee for president told Bloomberg that he has narrowed the field to "four or five politicians from within the party's establishment."

Trump wouldn't name any names, but said that some of the politicians on his short list are former rivals who dropped out of the race for the Republican nomination. One of these former rivals has refused to endorse Trump, but the billionaire real-estate mogul said he thinks this person will "come over to [his] side."

Marco Rubio, the Florida senator who blasted Trump during the primaries before indicating that he'd support him, has declined to offer a formal endorsement. Ted Cruz, the Texas senator and another former Trump rival, said Tuesday he's still "assessing" whether or not to endorse Trump.

Among the vice-presidential contenders are two "respected military officials," Bloomberg reported, but Trump told the news outlet that he probably won't pick either of them because he thinks he's "going to do very well on national security."

He ruled out a business-oriented pick on the basis that he doesn't "need that type of ability."

An experienced politician, on the other hand, has already been vetted by the media and public, so it's less likely that people would "find out that they were doing terrible, terrible things with their life," Trump said.

Trump ruled out Rick Perry, the former Texas governor who ran for president in 2012 and 2016, but said he'd "like to get him involved in some capacity at a high level."

"I think he's very good," Trump told Bloomberg. "I think he's very very good. He's also very good on the border."