 -- President Donald Trump's national security adviser declined to say if the president confronted Russian officials about the country's interference in the 2016 U.S. presidential election during a meeting at the White House earlier this month, telling ABC News Chief Anchor George Stephanopoulos "there already was too much that's been leaked from those meetings."

"One of the things that I'm most concerned about is the confidence, the confidentiality of those kind of meetings, as you know, are extremely important," McMaster said in an exclusive interview that aired on "This Week" Sunday. "I'm really concerned about these kind of leaks because it undermines everybody’s trust in that kind of an environment where you can have frank, candid and oftentimes unconventional conversations to try to protect American interests and secure the American people."

"The initial leak that came out was a leak about concerns about revealing intelligence sources and methods," McMaster said referring to a report from The Washington Post Monday, which stated the president revealed highly classified information to Russian foreign minister Sergey Lavrov and Russian ambassador Sergey Kislyak which "jeopardized a critical source of intelligence on the Islamic State."

"Information that's not even part of the president's briefing. And so in a concern about divulging intelligence they leaked actually not just the information from the meeting, but also indicated the sources and methods to a newspaper," McMaster said on "This Week."

"I take your point on that, although there is also the question of whether or not it was right for the president to give that information to the Russians," Stephanopoulos responded. "But I just asked the direct question: Did the president confront the Russians on their interference in our election?"

McMaster still did not answer.

"I'm not going to divulge more of that meeting," McMaster said. "Those meetings, as you know, are supposed to be privileged. They're supposed to be confidential."

The New York Times reported Friday that President Trump told Russian officials during their May 10 White House meeting that hisfiring of former FBI Director James Comey eased "great pressure" on him, while calling Comey "crazy, a real nut job."

When asked by Stephanopoulos about the report, McMaster -- who was in the Oval Office meeting with Trump and the Russian officials – would not deny the comments.

"I don't remember exactly what the president said," Trump's national security adviser said. "The notes that there apparently have I do not think are a direct transcript. But the gist of the conversation was that the president feels as if he is hamstrung in his ability to work with Russia to find areas of cooperation because this has been obviously so much in the news. And that was the intention of that portion of that conversation."

Stephanopoulos pressed, “You have the President of the United States telling the Russian foreign minister, in their first meeting, that that the pressure is off because he's fired the FBI director investigating Russian interference in the campaign. Does that seem appropriate to you?”

“As you know it’s very difficult to take a few lines, to take a paragraph out of what are what appear to be notes of that meeting. And to be able to see the full context of the conversation,” McMaster responded. “The really purpose of the conversation was to confront Russia on areas, as I mentioned, like Ukraine and Syria, their support for Assad, and their support for the Iranians. While trying to find areas of cooperation as in the area of counterterrorism and the campaign against ISIS. And so, that was the, that was the intent of that conversation was to say what I'd like to do is move beyond all of the Russia news so that we can find areas of cooperation.”

In a statement Friday to ABC News, White House Press Secretary Sean Spicer did not dispute The New York Times account, saying, “By grandstanding and politicizing the investigation into Russia’s actions, James Comey created unnecessary pressure on our ability to engage and negotiate with Russia.”

Asked if Comey’s “grandstanding” hurts our ability to deal with Russia, McMaster said on “This Week,” “I think what's been hurting our ability to deal with Russia more than any other factor has been Russia's behavior.”

“Since President Trump has taken action in Syria, we think that there may be opportunities to find areas of cooperation in places like Ukraine, in places like Syria in particular,” McMaster added.