President Donald Trump's son-in-law, Jared Kushner, now a senior White House adviser, and his former national security adviser, Mike Flynn, met with Russian Ambassador Sergey Kislyak at Trump Tower in December, White House Director of Strategic Communications Hope Hicks confirmed to ABC News.

The news of the meeting -- first reported by the New York Times -- comes on the heels of Attorney General Jeff Sessions' admission that he also met with Kislyak twice during the campaign, but failed to mention the encounters when questioned under oath during his confirmation hearing.

It was not clear what was discussed during the meeting between Kushner, Flynn and Kislyak.

Sessions, who was a frequent Trump surrogate, today promised to recuse himself from any probes related to the campaign's alleged contacts with the Russians. But he denied having meetings "with Russian operatives or Russian intermediaries about the Trump campaign."

Flynn's contacts with the Russian ambassador during the same period also received intense scrutiny. The former Army lieutenant general was forced to resign after news broke that he had misled Vice President Mike Pence about the nature of his conversations with Kislyak.

Flynn and the ambassador exchanged text messages on Christmas and spoke by phone on Dec. 29 -- the day the Obama administration imposed sanctions on Russia for its interference in the 2016 election. Flynn discussed the sanctions with the ambassador on that call.

The FBI, as well as several congressional committees, are investigating alleged contacts between Trump associates and Russian intelligence operatives during the presidential campaign.

The president, who has acknowledged that Russia was likely behind the hack of the Democratic National Committee, has repeatedly denied any contacts between his campaign and the Russians.

"Look, how many times do I have to answer this question? Russia is a ruse," Trump said at a press conference last month. He has also called the allegations about Russia "fake news."

Additional reporting by John Santucci.