Photo: Donald Trump and Sergey Lavrov met at the White House last week. (Russian Foreign Ministry/AP)
US President Donald Trump has defended revealing information to Russian officials, saying in a pair of tweets he shared "facts pertaining to terrorism and airline flight safety" and had "the absolute right" to do so.
- Russia's foreign ministry reportedly says Donald Trump did not reveal information
- White House declares allegations are incorrect
- House Speaker Paul Ryan demands a full explanation of what happened
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....
It came as the Kremlin described the reports Mr Trump had disclosed classified intelligence as "complete nonsense".
"It's not a subject for us, it's the latest piece of nonsense. We don't want to have anything do to with this nonsense," Kremlin spokesman Dmitry Peskov said.
"It's complete nonsense, not a subject to be denied or confirmed."Earlier, a Washington Post story alleged Mr Trump jeopardised a key intelligence source on the Islamic State terrorist group by disclosing it during a meeting with Mr Lavrov and Russian ambassador Sergey Kislyak at the White House.
The White House declared the allegations incorrect.
"The story that came out tonight as reported is false," Mr Trump's national security adviser HR McMaster told reporters, adding that the leaders reviewed a range of common threats including to civil aviation.
"At no time were intelligence sources or methods discussed. The president did not disclose any military operations that were not already publicly known. I was in the room. It didn't happen."
Video: White House National Security Adviser HR McMaster denies Trump revealed classified information to Russia (ABC News)
The White House also released a statement from Secretary of State Rex Tillerson, who said the Oval Office meeting focused on counter-terrorism, and from Deputy National Security Adviser Dina Powell, who called the Washington Post story false.
Video: Beverley O'Connor speaks to former US State Department official Max Bergmann (The World)
The newspaper had cited current and former US officials as its sources.
The Washington Post said the information Mr Trump relayed to the Russian pair had been provided by a US partner through a highly sensitive intelligence-sharing arrangement.
The partner had not given Washington permission to share the material with Moscow, and Mr Trump's decision to do so risks cooperation from an ally that has access to the inner workings of the IS militant group, the Post said, citing the unnamed officials.
Trump briefed on 'great intel every day'During his Oval Office meeting with Mr Lavrov and Mr Kislyak, Mr Trump went off-script and began describing details about an IS threat related to the use of laptop computers on aircraft, the officials told the Post.
Mr Trump appeared to be boasting about his knowledge of the looming threats, telling them he was briefed on "great intel every day", an official with knowledge of the exchange said, according to the Post.
Democrat Dick Durbin called Mr Trump's conduct "dangerous" and "reckless", while Bob Corker, the Republican head of the Senate Foreign Relations Committee, called the allegations "very, very troubling" if true.
The incident will also heighten Mr Trump's strained relations with intelligence workers and former officials, who view Russia as an adversary.
Even before he was inaugurated, intelligence professionals worried about sharing classified information with Mr Trump, who often shoots from the hip.
If true, the breach was ill-timed, coming a day after Mr Trump fired former FBI director James Comey, who was leading an investigation into Russian meddling in the presidential election.
Mr Trump's first national security adviser, Michael Flynn, was fired after he misled Vice-President Mike Pence about conversations he had with Mr Kislyak.
The CIA and the Office of the Director of National Intelligence declined to comment on the Washington Post story.