Donald Trump's national security advisor on Tuesday denied the US president had caused a "lapse in national security" following reports he disclosed highly-classified information about the Islamic State group to Russian officials.

"The premise of that article is false, that in any way the president had a conversation that was inappropriate or that resulted in any kind of lapse in national security," National Security Advisor H.R. McMaster told a White House briefing.

Asked about concerns Trump could have jeopardized US intelligence relationships by sharing with Russia information supplied by an ally, McMaster responded: "I'm not concerned at all. The conversation was wholly appropriate."

He then revealed that Trump was not briefed on the source of the information shared with Russian Foreign Minister Sergei Lavrov and Moscow's ambassador to the US, Sergey Kislyak.