Former CIA Director John Brennan on Friday had harsh words for President Donald Trump, calling the president "unstable, inept, inexperienced, and also unethical," The Hill reported.

In an interview on MSNBC, Brennan, who served under former President Barack Obama, said Trump was "ill-prepared" to take on the duties of president. He had particular dire warnings when it came to Trump's ability to handle international issues, such as the threat posed to the U.S. by Russia's President Vladimir Putin and North Korea's nuclear missile program.

"[O]ur country needs to have confidence that we're going to be able to deal with Mr. Putin, who is flexing his muscles once again on the military front, that we can deal with North Korea, that we can deal with these issues. And if we have somebody in the Oval Office who is unstable, inept, inexperienced, and also unethical — we really have rough waters ahead.

"It is no secret to anybody that Donald Trump was very ill-prepared and unexperienced in terms of dealing with matters that a head of state needs to deal with, head of government, and I think this is now coming to roost," Brennan said.

Brennan also criticized the president for taking issue this week with actor Alec Baldwin over his "Saturday Night Live" Trump impression rather than respond to Putin's announcement on Thursday claiming Russia had developed strategic weapons that would cause missile defense systems to be "useless."

"When I hear what Vladimir Putin was saying just yesterday about the nuclear capabilities he has, the president of the United States is tweeting about Alec Baldwin this morning, I mean, where is your sense of priorities?" Brennan asked.

"I think a lot of Americans are looking at what's happening with a sense of — this is surreal," he added.

White House press secretary Sarah Huckabee Sanders rejected Putin's statements, telling CNN it was not news to U.S. government officials.

"President Putin has confirmed what the United States government has known all along, which Russia has denied. Russia has been developing destabilizing weapons systems for over a decade, in direct violation of its treaty obligations," Sanders said.

"U.S. defense capabilities are and will remain second to none, and now because of the new defense budget of $700 billion, our military will be far stronger than ever," Sanders added. "As the president's nuclear posture review made clear, America is moving forward to modernize our nuclear arsenal and ensure our capabilities are unmatched."