Arizona senator John McCain says the mounting controversies surrounding the Trump administration are reaching the level of Watergate.

"It's reaching the point where it's of Watergate size and scale," he said Tuesday during a dinner in his honor at the International Republican Institute. "It's a centipede and the shoe continues to drop. Every couple of days there's a new aspect."

His remarks came after a barrage of reports related to the Trump administration, starting with the sudden firing of FBI director James Comey last Tuesday. Comey was overseeing an investigation into the nature of any potential links between the Trump campaign and the Kremlin.

Next up was a Washington Post report revealing that the president spilled classified information to Russian officials at the White House last week that could be reverse engineered to discover sources and methods. Then on Tuesday, the New York Times reported out a February memo by Comey, which described a request by Trump to Comey to drop the investigation into fired national security adviser Mike Flynn.

Asked what Trump should do, McCain again referred to the Nixon presidency and said, "get it all out" before the public, "no matter what it is."

"Same thing that you and others advised Richard Nixon," he said. "It's not going to be over until every aspect of it is thoroughly examined and the American people have made a judgment, and the longer you delay, the longer it's going to last."

McCain appeared confident that Comey would testify before Congress.

"It's pretty clear that Comey will testify. He will testify in an open hearing, and the American people deserve that," he said.

The Arizona senator lamented that the White House controversies were getting in the way of legislating.

"We have to do a reform of Obamacare, a replacement, we have to work on the tax reform, we have a number of agenda items," he said. "I have to honestly speak to truth to my Republican friends. I don't see how you can say that just the confirmation of Judge Gorsuch is enough of a record for us to stand before the American people in 2018."

"I think we've got a lot more to go, and unfortunately, we seem to be sidelined by this situation," he said. "I don't think this is good for the country."

The administration has a strong national security team, McCain said, but its work is being hobbled by the scandals surrounding the administration.

"What's kind of sad about all this is you have such a strong national security team in this most dangerous time," he said. "And yet they're not able to function because everything seems to be siphoned into this issue of Russia."