President Trump continued Friday to defend his choice of Matthew Whitaker as acting attorney general following the resignation of Jeff Sessions earlier in the week.

In a series of late-night tweets from Paris, Trump seemed to continue statements he made in Washington earlier in the day in defense of Whitaker, who served as Sessions' chief of staff until his boss resigned Wednesday at the request of the president.

Just before leaving for Paris, where he will take part in events commemorating the 100th anniversary of the end of World War I, Trump said he “didn’t know” Whitaker but the former U.S. attorney from Iowa was “highly thought of."

His remarks contradicted comments he made on Fox News last month when he said Whitaker was a "great guy" and "I mean, I know Matt Whitaker."

"Matthew G. Whitaker is a highly respected former U.S. Attorney from Iowa. He was chosen by Jeff Sessions to be his Chief of Staff. I did not know Mr. Whitaker. Likewise, as Chief, I did not know Mr. Whitaker except primarily as he traveled with A.G. Sessions. No social contact...," the president tweeted Friday.

He later tweeted that Iowa Gov. Joni Ernst, U.S. Sen. Chuck Grassley, R-Iowa, and U.S. Ambassador to China Terry Branstad were among those who thought "very highly" of Whitaker.

Senate Majority Leader Mitch McConnell, R-Ky., predicted Friday that Trump will nominate a permanent attorney general "pretty quickly" and said Whitaker would be a "very interim AG."

"The president has said repeatedly he's not going to dismiss the Mueller investigation," McConnell told reporters at Kentucky's Capitol in Frankfort. "He's said repeatedly it's going to be allowed to finish. That also happens to be my view."

Whitaker’s selection has roiled Democrats, who believe he could undermine Special Counsel Robert Mueller's investigation into possible links between the Trump election campaign and Moscow.

Eighteen state attorneys general signed a document Thursday calling on Whitaker to recuse himself from overseeing the probe, citing critical comments he made about the investigation during media appearances before joining the Justice Department last year.

Trump has brushed off those concerns, saying Friday, “This only comes because anybody that works for me, they do a number on them. All the time I’m watching many different people go on many different shows saying many different things. That doesn’t mean they’re unqualified.”

Some of Whitaker's criticisms of the Russia probe include an op-ed article in which he said Mueller would be straying outside his mandate if he investigated Trump family finances and a radio interview where he said no evidence of collusion between Russia and the Trump campaign existed.

Sen. Susan Collins, R-Maine, on Friday said she wants the Senate to debate placing restrictions on Trump's ability to remove Mueller.

Speaking in Brunswick, Collins said Whitaker's comments on the probe had her "very concerned" about his appointment, adding that a bill would pressure Trump to let the investigation run its course.

"I recognize that the president is never going to sign such a bill, but I think Senate debate and passage of the bill would send a very strong message to the president," she said.

In a statement to Justice Department employees, Whitaker said Friday: "As we move forward, I am committed to leading a fair Department with the highest ethical standards, that upholds the rule of law, and seeks justice for all Americans."

Some have publically wondered if Whitaker is even eligible for the job. Trump argues that since Whitaker was confirmed 14 years ago as the U.S. attorney for southern Iowa, he doesn’t need Senate confirmation.

Then there’s his association with a Florida company that Federal Trade Commission said bilked thousands of consumers out of millions of dollars by promising lucrative patent agreements to investors, the New York Times reported.

The company, World Patent Marketing, was shut down by a federal judge last year.

The Associated Press contributed to this report.