President Donald Trump in March sought to ease Russian President Vladimir Putin's concerns that administration officials had been trying to block a phone call between the two, The New York Times reported Monday.

After Putin told Trump that White House advisers had tried to interfere, Trump reportedly called them "stupid people" and told Putin he "shouldn't listen to them."

The report emerged ahead of a scheduled NATO summit in Brussels on Wednesday. Trump is expected to participate in a one-on-one meeting with Putin in Finland next week.

During a phone call with Russian President Vladimir Putin in March, President Donald Trump reportedly sought to ease Putin's concerns that administration officials had been trying to block the conversation between the two.

After Putin said the officials had tried to interfere, Trump told Putin, "Those are stupid people; you shouldn't listen to them," The New York Times reported Monday, citing a person with direct knowledge of the conversation.

On the call, Trump congratulated Putin on what was widely believed to be a sham reelection victory, ignoring his national security advisers and a briefing with the instruction "DO NOT CONGRATULATE."

Trump also invited Putin to the White House, a Kremlin aide named Yuri Ushakov told journalists in April. It would be Putin's first White House visit since 2005.

Trump has long admired Putin and believes the US and Russia can be allies, according to multiple reports detailing Trump's attitude toward Putin and Russia. The Times report about Trump's interaction with Putin comes ahead of a scheduled NATO summit in Brussels on Wednesday and a planned one-on-one meeting with Putin in Finland next week.

Democratic Sen. Mark Warner of Virginia described Trump's desire to make nice with Russia as "very problematic."

Putin and Trump. Associated Press

"This administration seems to treat our allies as adversaries and treat our adversaries or potential adversaries like their friends," Warner told CNN on Monday.

Trump "doesn't at least seem to reflect that what we share in common with our NATO allies is not only a common defense alliance, but we have a shared belief in rule of law — we have a shared belief in democracy," Warner added.

"Mr. Putin represents none of those values," he said, "yet you see out of the president constant acclaim."

Trump's relationship with NATO countries has been tenuous since before he took office. He has often railed against the US's key allies, accusing them of fueling trade and spending deficits with the US.

"The United States is spending far more on NATO than any other Country," Trump claimed in a tweet on Monday. "This is not fair, nor is it acceptable."

Trump has also floated the idea of allowing Russia back into the Group of 7. In 2014, Russia's membership in what was formerly the G8 was revoked after it annexed Crimea.

"Russia should be in this meeting," Trump said in June as he left for the G7 summit. "They should let Russia come back in, because we should have Russia at the negotiating table."

This approach to diplomacy with Russia has foreign-policy experts worried, particularly amid the US intelligence community's conclusion that Russia meddled in the 2016 US presidential election and accusations that Russia carried out a nerve-agent attack in the UK.

"In normal times, a president of the United States would rally the allies, develop a unified approach, and go with a strengthened hand to negotiations with the president of Russia, rather than reducing his own leverage," Alexander Vershbow, a former NATO deputy secretary general, told The Times.