Russia's Foreign Ministry has rebuked claims that U.S. President Donald Trump divulged highly classified information to Russian officials during a visit to the Oval Office, calling them "harmful" and "dangerous."

Maria Zakharova, Russian Foreign Ministry spokeswoman, dismissed the claims in a Facebook post Tuesday, the day after reports emerged that Trump had revealed intelligence about a planned Islamic State operation to Russia's foreign minister, Sergei Lavrov, and Ambassador Sergey Kislyak.

"Guys, have you been reading American newspapers again? Don't read them," wrote Zakharova.

"You can use them in all sorts of ways, but don't read them – it's not just bad for you, lately it's been dangerous."

The information the Trump relayed was "so sensitive that details have been withheld from allies and tightly restricted even within the U.S. government, officials told The Wall Street Journal.

The White House has since denied the claims.

Such a disclosure of intelligence to an adversary would typically be illegal. However, the president has authority to declassify confidential government information, meaning that – if true – the claims are unlikely to be considered a breach of the law.

Russia's Interfax news agency, citing the Russian Foreign Ministry, said the reports are "fake."

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Correction: Maria Zakharova is spokeswoman for the Russian Foreign Ministry. An earlier version misstated her title.