Nov. 18 (UPI) — President Donald Trump said he is considering making changes in as many as five Cabinet positions during an interview with Fox News that aired Sunday.

Appearing on Fox News Sunday, Trump told Chris Wallace he values the ability to be flexible with his staff amid speculation Department of Homeland Security Kirstjen Nielsen and White House chief of staff John Kelly may soon depart from the White House.

“I have three or four or five positions that I’m thinking about. Of that, maybe it’s going to end up being two. But I need flexibility,” Trump said.

Trump told Wallace he was looking for Nielsen to improve her handling of the U.S.-Mexico border.

“I like her very much I respect her very much I’d like her to be much together on the border. Much tougher. Period,” Trump said.

The president also said he and Kelly “get along well,” but said Kelly was likely to “move on,” suggesting he may not remain as chief of staff with the White House through 2020.

“There are certain things I love what he does and there are certain things that I don’t like that he does — that aren’t his strength,” Trump said. “It’s not that he doesn’t do — you know he works so hard. He’s doing an excellent job in many ways. There are a couple of things where it’s just not his strength. It’s not his fault, it’s not his strength.”

Addressing the replacement of one of his administration’s most recent departures, Trump said he wasn’t aware that Acting Attorney General Matthew Whitaker had been critical of Special Counsel Robert Muller’s investigation into his possible role in Russian interference in the 2016 election when he selected him to replace departing Attorney General Jeff Sessions.

“I did not know he took views on the Mueller investigation as such,” Trump said.

He added he “would not get involved” in Whitaker’s decisions overseeing the Mueller probe as attorney general.

“It’s going to be up to him,” Trump said. “I think he’s very well aware politically. I think he’s astute politically. He’s a very smart person. A very respected person. He’s going to do what’s right. I really believe he’s going to do what’s right.”