President Trump on Monday said the whistleblower whose complaint sparked an impeachment inquiry must be identified and testify to Congress after Rep. Adam Schiff said the person may not appear because of safety concerns.

“Adam Schiff now doesn’t seem to want the Whistleblower to testify. NO! Must testify to explain why he got my Ukraine conversation sooo wrong, not even close,” Trump wrote on Twitter. “Did Schiff tell him to do that? We must determine the Whistleblower’s identity to determine WHY this was done to the USA.”

Schiff, the chair of the House Intelligence Committee, said the safety of the whistleblower who revealed Trump’s call to Ukrainian President Volodymyr Zelensky is paramount.

“Before the president started threatening the whistleblower … we were interested in having the whistleblower come forward. Our primary interest right now is making sure that that person is protected,” the California Democrat said on CBS’ “Face the Nation” Sunday.

Besides, Schiff said, the White House has released a rough transcript of the July 25 conversation between Trump and Zelensky.

“Given that we already have the call record, we don’t need the whistleblower who wasn’t on the call to tell us what took place during the call,” Schiff said.

The complaint filed to the inspector general of the intelligence community claimed Trump pressed Zelensky to launch an investigation into Democratic presidential candidate Joe Biden and his son Hunter.

Trump has defended the conversation, calling it “perfect” and “appropriate.”

House Speaker Nancy Pelosi launched the impeachment inquiry upon learning of the whistleblower’s complaint.

A second whistleblower has since come forward.