President Donald Trump on Wednesday named Richard Grenell as acting director of national intelligence.

Grenell, a staunch supporter of Trump's policies, is the U.S. Ambassador to Germany.

“I am pleased to announce that our highly respected Ambassador to Germany, @RichardGrenell, will become the Acting Director of National Intelligence,” Trump said in a tweet. “Rick has represented our Country exceedingly well and I look forward to working with him.”

The move makes Grenell the most senior openly gay official in the Trump administration.

Grenell served as a US spokesman at the United Nations during former President George W. Bush's administration. He worked on Arizona Senator John McCain's unsuccessful presidential campaign. In 2012, he joined the presidential campaign of Mitt Romney, serving as the Republican nominee's foreign policy spokesman, but resigned less than two weeks later amid growing pressure from social conservatives over his sexual orientation. Prior to his ambassadorship, Grenell appeared on Fox News Channel as a foreign affairs commentator and was one of Trump's earliest foreign policy supporters.

Senator Mark Warner, a Democrat from Virginia and vice-chair of the Senate Intelligence Committee, criticized Grenell's appointment, saying he lacks experience.

“The intelligence community deserves stability and an experienced individual to lead them in a time of massive national and global security challenges,” Warner said. “And at a time when the integrity and independence of the Department of Justice has been called into grave question, now more than ever our country needs a Senate-confirmed intelligence director who will provide the best intelligence and analysis, regardless of whether or not it’s expedient for the president who has appointed him.”

Trump has previously skirted around the Senate by putting people in acting positions that do not require Senate confirmation without naming a permanent replacement.