WASHINGTON — Sen. John McCain, the powerful chairman of the Senate Armed Services Committee, sent his first shot across the bow of President-elect Donald Trump’s national security plans Tuesday, saying that any attempt to “reset” relations with Russia was unacceptable.

“With the U.S. presidential transition underway, Vladimir Putin has said in recent days that he wants to improve relations with the United States,” McCain, R-Ariz., said in a statement released by his office.

“We should place as much faith in such statements as any other made by a former KGB agent who has plunged his country into tyranny, murdered his political opponents, invaded his neighbors, threatened America’s allies, and attempted to undermine America’s elections,” he said.

McCain gave tepid support to Trump after the Republican nominating convention, then withdrew it following the October leak of a recording revealing Trump’s demeaning remarks about women, and then declined to speak about him as he headed toward his own successful reelection last week.

His comments on Russia followed a phone call between Trump and Putin and came amid reports of upheaval in the national security transition.

In their conversation, the Kremlin said, Putin and Trump agreed that U.S.-Russia relations were “unsatisfactory” and vowed to work together to improve them. Trump’s office later said that they had discussed shared threats and challenges and the long-term relationship between them.

In his statement, McCain pointed out that Russia, in support of Syrian President Bashar Assad, resumed large-scale bombardment Tuesday in Syria.

“The Obama administration’s last attempt at resetting relations with Russia culminated in Putin’s invasion of Ukraine and military intervention in the Middle East,” McCain said. “At the very least, the price of another ‘reset’ would be complicity in Putin and Assad’s butchery of the Syrian people.”

Sen. Lindsey Graham, R-S.C., a foreign policy hawk and friend of McCain’s, said he plans to hold hearings on “Russia’s misadventures throughout the world.”

Among the areas he wants to examine is whether Russia had a role in the hacking of Democratic Party organizations before the election.

“When it comes to all things Russia, I am going to be hard ass,” said Graham, who chairs the Senate subcommittee that controls foreign aid spending. Republicans can’t “sit on the sidelines” and let allegations that a foreign government interfered in a U.S. election go unanswered because it may have been temporarily beneficial to the GOP’s cause, he said.

“This is a defining moment for the country,” Graham said. “I want a good relationship with Russia, but things have to substantially change.”