(The Hill) — Former President Trump told reporters Saturday he’s made up his mind about who will be his running mate in November, but he has yet to tell anyone who it is.

Trump told NBC News ahead of a rally in Philadelphia that he’s settled on a vice presidential choice.

“In my mind, yeah,” Trump said when asked if he’s decided.

Asked if his pick knows it’s them, Trump responded, “No, nobody knows.”

The selection process for Trump’s running mate has ramped up in recent weeks as several candidates received vetting materials from the campaign. Trump has said he may announce his choice at the Republican National Convention in Milwaukee next month.

Sources familiar with the process have told The Hill the front-runners for the position are North Dakota Gov. Doug Burgum (R), Sen. J.D. Vance (R-Ohio) and Sen. Marco Rubio (R-Fla.).

Others who received vetting materials and are under consideration include Sen. Tim Scott (R-S.C.), Sen. Tom Cotton (R-Ark.), Rep. Elise Stefanik (R-N.Y.), Rep. Byron Donalds (R-Fla.) and former Secretary of Housing and Urban Development Ben Carson.

Trump has praised each of those individuals at various times, though he has downplayed the impact his selection might have on the end result in November.

“It’s never really had that much of an effect on an election,” Trump told Fox News earlier this year.