McMaster joined host Martha MacCallum one day after Trump told rallygoers in Ohio: "I like Putin, he likes me. You know, we get along."
"I don’t understand it," McMaster said Tuesday, "and I think it does play into Putin’s hands in large measure because Putin is the best liar in the world.
"And, you know, President Trump is the third of three presidents who will eventually figure this out," McMaster added, "But it came late to other presidents as well. I mean, you might remember President George W. Bush ‘looking into Putin’s soul'; or President Obama leaning over to President [Dmitry] Medvedev – who was keeping the seat warm for President Putin to come back – saying, ‘Hey, I can work with you more after the  election’; or Secretary [of State Hillary] Clinton bringing the reset button."
While critics have taken issue with Trump's warm personal rhetoric toward Putin, the White House has repeatedly touted the administration's willingness to impose sanctions on Russia.
"I wish the President would be tougher on Putin publicly," McMaster said later in the interview, "because I think what Putin will do is, he’ll push as much as he can until there are costs imposed on him that are beyond those that are factors at the beginning of his decisions."
The former national security adviser also defended Trump's use of the term "China virus" to describe the coronavirus, a phrase many have described as racist.
"Well, it is accurate to call it the ‘China virus,’" McMaster said, "and I think what’s important to know is that the best way to deal with a pandemic is to stop it before it becomes a pandemic, at its source. And thanks to the Chinese Communist Party, we couldn’t do that.
"And so, this is a virus that’s sort of inflicted on the world by the Chinese Communist Party’s repression of the truth," he added.