Rep. Adam Schiff continued his public feud with President Trump on Sunday, calling him “weak” and promising to get to the bottom of Matthew Whitaker’s appointment as acting attorney general.

Schiff, D-Calif., who has long been a fierce critic of the president, said on CNN’s “State of the Union” that Trump was “not being honest” with Americans about the murder of Washington Post writer Jamal Khashoggi by Saudi operatives in Turkey and questioned whether the president may have some personal business interests with Saudi Arabia.

“I think, in part, he feels by saying that we don't know or that the world is a dangerous place or everybody does it, he thinks it makes him look strong,” Schiff said. “It actually makes him look weak.”

He added: “Whether this is simply an affinity he has for autocrats -- he seems to choose them repeatedly over his own intelligence agencies -- or whether there’s a financial motivation, in his own personal finances, we don’t know. Of course he has openly bragged about how many millions he makes from Saudi Arabia. Is his personal financial interest driving U.S. policy in the Gulf?

On the appointment of Whitaker, Schiff said that he would want the acting attorney general to appear before Congress when the Democrats take over the lower house in January, to answer questions about the possibility of obstruction of justice and the future of Special Counsel Robert Mueller’s Russia investigation.

“We are going to bring Whitaker before the Congress, assuming he’s still in the position at the time when Democrats take over,” Schiff said. “One of the key decisions that the attorney general will make, whoever’s in that role, is when Bob Muller puts together a report on, among other things obstruction of justice, will that report be shared with the American people?

Schiff added: “The American people need to know, they deserve to know, whether their president is interfering with the impartial administration of justice.

Schiff, who is currently the ranking Democrat on the House Permanent Select Committee on Intelligence, looks to become the committee chairman when Democrats take over the House in January and would have broad authority to decide who gets called before the committee to testify.

Schiff and the president have been in the middle of a public feud ever since the California Democrat called Trump’s appointment of Whitaker as acting attorney general unconstitutional.

Trump said in a tweet that Schiff shouldn't complain that Whitaker wasn't confirmed by the Senate because neither was Mueller, who's investigating 2016 election interference and possible ties between Moscow and Trump's presidential campaign.

“So funny to see little Adam Schitt (D-CA) [sic] talking about the fact that Acting Attorney General Matt Whitaker was not approved by the Senate, but not mentioning the fact that Bob Mueller (who is highly conflicted) was not approved by the Senate!” Trump said in a tweet.

The Justice Department appoints special counsels.

Critics contend Trump illegally sidestepped procedure by appointing Whitaker over Deputy Attorney General Rod Rosenstein, who has been confirmed.

Schiff responded to Trump’s tweet, saying: "That's a good one. Was that like your answers to Mr. Mueller's questions, or did you write this one yourself?"

The Associated Press contributed to this report.