(CNN) President Donald Trump is increasingly agitated at the slow pace of confirmations in the Senate and blasted Democrats Monday for delaying votes on many of his nominees to top government posts -- including his pick to be ambassador to Germany.

"Hard to believe Obstructionists May vote against Mike Pompeo for Secretary of State," Trump tweeted. "The Dems will not approve hundreds of good people, including the Ambassador to Germany. They are maxing out the time on approval process for all, never happened before. Need more Republicans!"

Trump was highlighting the long-stalled nomination of Richard Grenell, a close political ally and his choice to be the top US diplomat in the major European country. Many Democrats loudly oppose Grenell and are refusing to give consent for a quick vote on his confirmation, even though there are likely enough GOP votes to confirm him.

Grenell, who if confirmed would become one Trump's highest profile gay appointees, is a Republican who worked with Trump's national security adviser John Bolton at the United Nations. He was one of the President's earliest and most vocal foreign policy supporters, vociferously backing the real estate magnate at a time when many in the Republican foreign policy establishment were publicly and staunchly opposed to his candidacy.

Axios reported Monday that Grenell was spotted at Mar-a-Lago talking to Trump over the weekend. Sources close to Grenell said that Trump has told him he wants him to play a broader role in Europe beyond Germany, and that was true since his nomination -- even before Bolton was in the picture.

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