Sen. Bob Corker, the chairman of the Senate Foreign Relations Committee, was “really astounded” by President Donald Trump’s apparent dismissal of U.S. intelligence assessments that Saudi crown prince Mohammed bin Salman ordered the killing of Washington Post journalist Jamal Khashoggi last month.

“I never thought I’d see the day a White House would moonlight as a public relations firm for the Crown Prince of Saudi Arabia,” Corker said in statement on Twitter Tuesday, in response to a statement put out by the White House casting doubt on the Saudi government’s involvement in the journalist’s slaying.

Corker and Sen. Bob Menendez, the top Democrat on his committee, sent a letter to Trump on Tuesday to determine within 120 days whether bin Salman “is responsible for Mr. Khashoggi’s murder.”

The White House statement Tuesday, attributed to Trump, was roundly criticized after the president claimed “we may never know all of the facts” surrounding the slain journalists murder by Saudi government officials at the Saudi consulate in Istanbul, Turkey.

“Our intelligence agencies continue to assess all information, but it could very well be that the crown prince had knowledge of this tragic event — maybe he did and maybe he didn’t!” Trump said in the statement.