Democrats on Capitol Hill, however, were quick to register outrage over the reported incident -- and a few members of Trump's own party joined them. Countries who currently share intelligence with the U.S. also expressed concerns.
Here is a look at some of the reactions from lawmakers in Washington and around the world.
Speaker of the House Paul Ryan, R-Wis.
"We have no way to know what was said, but protecting our nation's secrets is paramount. The speaker hopes for a full explanation of the facts from the administration." - spokesman Doug Andres.
Sen. Lindsey Graham, R-S.C.
"If it's accurate, it would be troubling."
Rep. Frank LoBiondo, R-N.J.
Senate Minority Leader Chuck Schumer, D-N.Y.
House Minority Leader Nancy Pelosi, D-Calif.
“If news reports are true, President Trump has compromised a key source of intelligence collection against ISIS and jeopardized the security of the American people.
Even if President Trump unwittingly blew a highly classified code-word source to the Russians, that would be dangerous enough. If the president outed a highly classified code-word source intentionally, that would be even more dangerous.
Congress must be given a full briefing on the extent of the damage President Trump has done in compromising highly classified code-word intelligence to the Russians.”
Sen. Kamala Harris, D-Calif.
Sen. Dick Durbin, D-Ill.
Sen. Ed Markey, D-Mass.
Rep. Adam Schiff, D-Calif.
A senior European intelligence official told The Associated Press that his country might stop sharing information with the United States if the story about President Donald Trump's conversation with Russian officials could be confirmed.
The official told the AP on Tuesday that such a situation could represent "a risk for our sources."
Danny Yatom, the former director of Israel's spy agency, echoed that point, telling The Jerusalem Post that if the allegations were proven to be true, the incident “could lead to harm to the source.”
If true, Yatom described the conversation to the paper as a “grave violation” of intelligence sharing protocol.
“If someone gives the U.S. very sensitive information … it is prohibited to give the information to a third party –- for sure not to Russia, who has ties with Iran and Syria," Yatom told the Jerusalem Post.