Trump chose to mention the information in the "context of the conversation" with Russian Foreign Minister Sergei Lavrov, McMaster told reporters in the White House, calling it "wholly appropriate to that conversation" and "consistent with the routine sharing of information between the president and any leader with whom he's engaged".
On Monday, media reported that President Donald Trump had last week disclosed highly classified information on the so-called "Islamic State" (IS) terrorist group to the Russian foreign minister, Sergey Lavrov.
Suspicion of the Russians runs so deep in the U.S. administration that even a hint of liaison with them is frowned upon. Mr. Trump made a decision to share the details "in the context of the conversation", said Mr. McMaster, suggesting that it was a spontaneous move by the President and not a step he previously discussed with his advisers.
"At no time were intelligence sources or methods discussed, and the president did not disclose any military operations that were not already publicly known", McMaster said.
Reuters reports that Kremlin aide Yuri Ushakov later told journalists that Moscow had a written account of the Oval Office conversation, not a recording. Sounds like the type of high-level information whose disclosure could endanger its source.
Reporters started gathering in the hallway outside Press Secretary Sean Spicer's office right after the Post story broke.
That message was echoed by Yves Trotignon, a former counter-terrorism analyst for France's DGSE intelligence agency, now with risk consultant Riskeco, who said Trump violated a basic tenet of intelligence sharing.
Trump was later informed that he had broken protocol.
That key could be the downfall for Trump, who has skated on presidential exceptions to government conflict of interests laws and, as we distressingly learned on Monday, on releasing classified materials.
Trump's meeting with the Russians came last Wednesday, the day after he fired FBI Director James Comey, who was overseeing an investigation into Russian meddling in the US elections and possible ties between the Trump campaign and Russia.
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Recent updates to Google Home , which allows users to access Google Assistant, offer support for additional features. These three are able to integrate more deeply into their respective platforms, at least more than third-party apps.
Trumps first national security adviser, Michael Flynn, was sacked after he misled Vice-President Mike Pence about conversations he had with Kisylak.
The Israelis said they had full confidence in the intelligence-sharing relationship with the USA, contradicting reports earlier this year that the Israelis had considered withholding secrets from Trump, at the urging of American colleagues anxious about their own boss.
The report claims Trump shared a US ally's closely guarded intelligence on ISIS with the Russian ambassador and the foreign minister.
A USA administration official confirmed to AFP news agency on condition of anonymity that the original intelligence came from Israel.
It's also imperative that Congress get to the bottom of the new allegations of attempted meddling with Comey, which could turn out to be definitive evidence that Trump tried to influence the Justice Department and FBI investigation into links between his associates and Russian Federation. European allies have also privately expressed concern.
The question came during a press briefing ahead of Britain's June 8 election, which polls show May is on course to win, and in which national security is seen as one of her political strengths. But the chaos that is being created by the lack of discipline its creating an environment that I think makes it creates a worrisome environment..
In fact, McMaster said that Trump "was not even aware" of the provenance of the information he provided.
Reaction from Democrats on the House and Senate intelligence committees was full-throated.
United States presidents strive for strong relationships with their top intelligence advisors as soon as they come into office. CIA Director Mike Pompeo briefed the House Intelligence Committee late Tuesday in a closed session that officials said was previously scheduled.
Sen. Mark Warner, D-Va., tweeted: If true, this is a slap in the face to the intel community. Such sharing "could be a risk for our sources", the official said.