WASHINGTON — President Trump defended wanting to share terrorism intelligence with Russian officials in a White House meeting last week, saying he has the “absolute right” to do so.

“As President I wanted to share with Russia (at an openly scheduled W.H. meeting) which I have the absolute right to do, facts pertaining to terrorism and airline flight safety,” he said in a series of tweets on Tuesday. “Humanitarian reasons, plus I want Russia to greatly step up their fight against ISIS & terrorism.”

Trump’s messages came after his top foreign policy advisers raced to contain political damage from a Washington Post report that the president revealed to Russia’s foreign minister and ambassador highly classified information from a U.S. intelligence partner about an Islamic State plot. Trump was already fending off questions about his firing of FBI Director James Comey amid an investigation of possible collusion by Trump associates in Russian interference with the U.S. election.

The “story that came out tonight as reported is false,” White House National Security Adviser H.R. McMaster said at a hastily arranged appearance outside the White House on Monday. “At no time were intelligence sources or methods discussed, and the president did not disclose any military operations that were not already publicly known.”

“I was in the room. It didn’t happen,” McMaster said in a statement that lasted less than a minute. He left without taking questions.

According to the Post, the intelligence involved information about an Islamic State plot to use laptop computers as possible weapons aboard commercial aircraft and had been provided by a U.S. ally with access to the inner workings of the terrorist group. Trump’s admission that he shared information with the Russians raised questions about the right of the president to release sensitive intelligence, even classified information.

“Presidents have often revealed, on their own authority (and sometimes inadvertently), secrets about collection capabilities that the Intelligence Community would have preferred to have kept secret, because such exposure tends to make such collection more difficult,” Nicholas Dujmovic, a Catholic University professor who spent more than 25 years at the CIA, said in an email.

U.S. presidents including Richard Nixon, Jimmy Carter and Ronald Reagan have either intentionally or inadvertently released classified information about surveillance capabilities and information that was captured, he said.

“Presidents can do this; in a sense, they ‘own’ US secrets,” he said. “But in a larger sense, they are the custodians of the secrets that need to be kept for the sake of U.S. national security.”

The Post cited unnamed current and former U.S. officials with knowledge of the exchange, who said they recognized that it jeopardized intelligence capabilities. The Post said homeland security and counterterrorism adviser Thomas Bossert called the directors of the CIA and the National Security Agency afterward. One of his subordinates called for that portion of the discussion stricken from internal memos and circulation of a transcript limited to prevent sensitive details from being further distributed, the newspaper said.

The intelligence was held by the U.S. at one of the highest classification levels that would typically prevent it from being shared even with allies, according to the Post. While Trump didn’t reveal the specific methods that developed the information or sources, he described elements of a specific plot and the city in Islamic State’s territory where the threat was detected, the Post said.

That specific information could be enough to let the Russians identify the source and method, according to one intelligence official cited by the Post.

Russian Foreign Ministry spokeswoman Maria Zakharova ridiculed the Post report Tuesday, writing on Facebook that American newspapers “can be used for other things but there’s no need to read them — in recent times it’s not only harmful but dangerous.”

The revelation may have additional peril for Trump because during his campaign against Democrat Hillary Clinton last year, he repeatedly assailed her “careless” use of a private email system while she was secretary of state, a practice he argued could have exposed classified information. He claimed it made her unfit for the presidency. Surrogates at his campaign rallies led chants of “lock her up!”

Top lawmakers of both parties, while saying they weren’t able to comment on the substance of the report, said it raised new questions about the administration.

“We have no way to know what was said, but protecting our nation’s secrets is paramount,” said Doug Andres, a spokesman for House Speaker Paul Ryan. “The speaker hopes for a full explanation of the facts from the administration.”

“The White House has got to do something soon to bring itself under control and in order,” Republican Senator Bob Corker, the chairman of the Foreign Relations Committee, told reporters at the Capitol. “Obviously they’re in a downward spiral right now and they’ve got to figure out a way to come to grips with all that’s happening.”

Sen. Jack Reed, the ranking Democrat on the Armed Services panel, said sharing information without the permission of a foreign intelligence partner “violates a cardinal rule” of dealing with friendly agencies.

“If it’s accurate, it’s disturbing because it’s divulging information about operations in Syria which could be exploited not only by the Russians to interrupt intelligence operations that they feel are threatening to them,” Reed said.

The intelligence involved may be behind the U.S. announcement on March 21 that electronic devices larger than smartphones would be banned from cabins on flights originating from 10 airports in the Middle East and Africa. The Department of Homeland Security has been considering expanding the restriction to flights from Europe.

The president has broad authority to declassify information so it’s not likely he broke the law, according to the Post, even though he shared it with a U.S. adversary.

Trump met with Russian Foreign Minister Sergei Lavrov and Ambassador Sergey Kislyak one day after firing Comey, who was leading an investigation into possible collusion between Trump associates and Russian agents trying to interfere with the U.S. presidential election.

Trump has denied any connection to Russia while also questioning the assessment of U.S. intelligence agencies that the government in Moscow directed a campaign of hacking and disinformation to disrupt the election.

Bloomberg’s Laura Litvan, Steven T. Dennis, Jennifer Epstein, Stepan Kravchenko and Nafeesa Syeed contributed.