President Trump and University of California, Berkeley law professor John Yoo met face-to-face at the White House for the first time on Thursday, the lawyer confirmed to The Hill.

Yoo, one of the attorneys who wrote a memo defending interrogation methods including waterboarding under the George W. Bush administration, told the Las Vegas Review-Journal on Saturday that he met with Trump in the Oval Office for about an hour. 

“He was upbeat and energetic,” Yoo told the Review-Journal, but he declined to say what they talked about. He said Trump was not “Nixonian in the bunker and paranoid and dark.”

The law professor told the Review-Journal that White House counsel Pat Cipollone also was present.

Their meeting comes after Yoo wrote a piece for National Review in June asserting that the Supreme Court ruling that blocked Trump’s plans to end the Obama administration's Deferred Action for Childhood Arrivals program (DACA) could help the president institute future policies without congressional approval. 

In the piece, Yoo said Chief Justice John Roberts’s ruling “makes it easy for presidents to violate the law, but reversing such violations difficult,” adding that the Administrative Procedure Act would need to be used to undo presidential actions. 

Yoo told the Review-Journal that he spoke to Trump over the phone about his article and commented that the president “was really on top of things.”

During his “Fox News Sunday” interview last month, Trump said he intended to write his own immigration and health care plans in the next few weeks because of the Supreme Court ruling. 

“The Supreme Court gave the president of the United States powers that nobody thought the president had, by approving, by doing what they did — their decision on DACA,” Trump said. 

The president also promoted Yoo’s new book, “Defender in Chief: Donald Trump’s Fight for Presidential Power,” in a Saturday tweet. In the book, Yoo said he did not vote for Trump in the 2016 primary or general elections, saying he was worried Trump “would test, evade or even violate the Constitution,” according to the newspaper.

“Boy, was I wrong,” Yoo wrote. “Trump campaigns like a populist but governs like a constitutional conservative.”

The White House did not immediately return a request for comment.