President Trump Donald John TrumpBiden says voters should choose who nominates Supreme Court justice Trump, Biden will not shake hands at first debate due to COVID-19 Pelosi: Trump Supreme Court pick 'threatens' Affordable Care Act MORE briefly met with his attorney Rudy Giuliani Rudy GiulianiThe Hill's Campaign Report: GOP set to ask SCOTUS to limit mail-in voting CIA found Putin 'probably directing' campaign against Biden: report Democrats fear Russia interference could spoil bid to retake Senate MORE on Saturday as Giuliani faces a federal investigation over possible campaign finance violations, Bloomberg News reported.

The two men met Saturday night at Trump's Mar-a-Lago resort in West Palm Beach, Fla., where Trump spent the weekend ahead of this week's Christmas holiday. It was unclear what the two men discussed, according to Bloomberg. The White House did not immediately return a request for comment from The Hill.

A communications aide to Giuliani, Christianné Allen, tweeted a picture of herself next to a smiling Trump on Sunday morning, hours after the meeting occurred.

An enchanting evening celebrating the Christmas season & all of our winning! @realDonaldTrump pic.twitter.com/5PGi90HPOn — Christianné L Allen (@Christianne_L_A) December 22, 2019

Giuliani also remains under investigation for possibly failing to register as a foreign agent, the same charge that ensnared other members of Trump's inner circle, including Paul Manafort Paul John ManafortFBI official who worked with Mueller raised doubts about Russia investigation Our Constitution is under attack by Attorney General William Barr Bannon trial date set in alleged border wall scam MORE, his former campaign chairman.

The former New York City mayor has been at the center of the House's impeachment inquiry into Trump due to his efforts in Ukraine to uncover possibly damaging information on former Vice President Joe Biden Joe BidenBiden says voters should choose who nominates Supreme Court justice Trump, Biden will not shake hands at first debate due to COVID-19 Joe Biden should enact critical government reforms if he wins MORE, a top contender for the Democratic Party's 2020 nomination.

Trump's and Giuliani's efforts to convince Ukrainian officials, including the country's new president, Volodymyr Zelensky, to open criminal investigations into Biden ahead of the 2020 election have been characterized by critics as an attempt to solicit foreign interference in a U.S. election.