United States President Donald Trump allegedly disclosed highly-classified information to Russia’s foreign minister about a planned operation against the Islamic State group during their meeting last week, two officials told The Washington Post on Monday. One of the two officials said Trump had disclosed the information to Russian Foreign Minister Sergei Lavrov almost spontaneously.

The information was supplied by an ally of US. Although the president can choose to disclose any information, this particular case may hamper an intelligence-sharing agreement as the ally did not grant permission to share it with Russia, according to The Washington Post. “Trump revealed more information to the Russian ambassador than we have shared with our own allies,” the official told the daily.

Officials immediately went into damage control mode and informed the Central Intelligence Agency and National Security Agency about what had happened, reported Reuters..

However, the White House has refuted the allegations. “The story that came out tonight as reported is false,” said Trump’s National Security Adviser HR McMaster, according to BBC. He added that common threats were discussed but not “intelligence sources or methods”. McMaster further claimed that he was present when the discussions were being held. “The president did not disclose any military operations that were not already publicly known.”

Secretary of State Rex Tillerson and Deputy National Security Adviser Dina Powell corroborated McMaster’s version. They also added that the meeting was only on counterterrorism.

This comes at a time when Trump abruptly fired James Comey, the director of the Federal Bureau of Investigation, purportedly because of his handling of the Hillary Clinton emails controversy. Comey had also been leading an investigation into the Trump campaign’s ties to Russia.