Retired Army Gen. Barry McCaffrey said in an interview Monday that President Donald Trump’s comments about Russian President Vladimir Putin might be “the most anti-American statement” ever made by a U.S. president.

“How concerned are you about not just what the President is saying but the relationship that means the U.S. is going to have with Russia, where that goes from here?” MSNBC’s Hallie Jackson asked McCaffrey.

“I’m actually incredulous that the President would make a statement like that,” he replied. “One could argue that’s the most anti-American statement ever made by the president of the United States, to confuse American values with Putin.”

McCaffrey said it was “hard to know what to think” about Trump’s comments.

“He’s the commander in chief, but I do think we ought to feel fortunate that Secretary Jim Mattis is in charge of DOD,” he added later in the interview. “Because these erratic, impulsive and hostile statements are going to get us in trouble.”

In an interview with Fox’s Bill O’Reilly on Sunday, Trump dismissed concerns about Putin’s authoritarian regime by saying that the United States is not “so innocent.”

“We’ve got a lot of killers,” Trump said. “What, you think our country’s so innocent?”

Watch the exchange below: