It wasn't clear if Trump's remarks were meant to be in jest, and he gave no solid indication either way. In any case, the comments did not go down well among employees at the State Department, where many U.S. diplomats have felt ignored and badly treated by the Trump administration.

Some noted that locally hired staff members affected the most are crucial to American diplomats' work overseas.

A senior U.S. diplomat serving overseas called Trump's remarks "outrageous" and said it could lead more State Department staffers to head for the exits.

"This is so incredibly demoralizing and disrespectful to people serving their country in harm's way," the diplomat said.

"I kid you not, I have heard from three different people in the last five minutes," one State Department official told POLITICO shortly after Trump's comments. "Everyone seems pretty amazed. This statement is naive and shortsighted. It sends a terrible signal to local employees everywhere."

"THANK Putin?" another bewildered State Department official responded. "I don't have words that are printable to describe my reaction."

Nicholas Burns, who served as undersecretary of state for political affairs during the second Bush administration, called Trump's statement "shameful."

"He justifies mistreatment of U.S. diplomats by Putin," Burns wrote on Twitter.