Former U.S. Ambassador to Russia Michael McFaul was furious when he heard President Donald Trump celebrate Russian President Vladimir Putin's expulsion of 755 embassy employees from the country.

“I want to thank him because we’re trying to cut down our payroll and as far as I’m concerned I’m very thankful that he let go of a large number of people,” Trump told reporters during an impromptu press conference in Bedminster, New Jersey. “There’s no real reason for them to go back.”

McFaul, who served as the ambassador from 2011-2014 under former President Barack Obama also served as the former Special Assistant to the President at National Security Council. He knows first hand the strategic value of diplomats and staff living and working in Russia on behalf of the United States.

"Trump just applauded cuts of 755 in Russian embassy," McFaul said Thursday. "Maybe he should look to trim his own staff? You realize Mr. President that the State Dept organizes US delegations to [the Global Entrepreneurship Summit] -- those same people you just said were not needed in Russia."

He went on to allege that the comment from Trump proves that the president doesn't know anything about foreign diplomacy.

"Our diplomats, professional staff, and military serving in Russia provide Washington with invaluable information about Russia," McFaul continued. "Imagine wanting to know less about Russia's military modernization! That's what Trump praised today. Imagine wanting to know less about Russian foreign policy intentions and plans! That's what embassy personnel reductions will do. Imagine wanting to have less capability to gather data about dangerous transnational diseases originating in Russia! Trump seems to want that. Imagine dissing Americans -- patriots serving our country under difficult conditions in Russia -- to praise Putin. Our president did today."

You can see the full tweetstorm below: