Richard Grenell, a strong defender of President Donald Trump and the current U.S. ambassador to Germany, has been named to the key post of acting director of national intelligence (DNI).

Trump confirmed that Grenell had been appointed to the role, which involves overseeing the 17 U.S. intelligence agencies and counseling the president on intelligence-related national security issues, late on Wednesday evening.

"I am pleased to announce that our highly respected Ambassador to Germany, @RichardGrenell, will become the Acting Director of National Intelligence," the president tweeted. "Rick has represented our Country exceedingly well and I look forward to working with him."

Grenell, who Axios reported will be the first openly gay U.S. cabinet secretary, previously worked as a Republican political operative and was a U.S. spokesperson to the United Nations.

He also founded a public affairs consultancy, and makes regular TV appearances in support of the president.

The permanent DNI job was vacated by Dan Coats in August 2019. Joseph Maguire has been acting DNI since, and Grenell will become yet another "acting" head of a key agency. It's unclear whether Trump will try to appoint him permanently.

Top Pentagon official pushed out

It also emerged on Wednesday that the Pentagon's top policy official has resigned at the request of Trump, the latest Washington player to be pushed out in the fallout from the Ukraine scandal which led to the president's impeachment.

John Rood last year warned Trump against withholding aid to Ukraine, though CNN reported that he had disagreements with the White House on numerous issues.

Trump thanked Rood "for his service to our Country" in a tweet on Wednesday, while also sharing a Bloomberg story stating that the official "faced pressure to resign from some who lost confidence in his ability to carry out Trump agenda".

CNN reported that Rood, who served as under secretary of defense for policy, was skeptical over U.S. peace talks with the Taliban as well as the decision to scale down military exercises with South Korea, and had pushed for the administration to take a harder line on Russia.