House Minority Leader Nancy Pelosi (D-Calif.) on Saturday called for the suspension of Michael Flynn, President Donald Trump’s national security adviser, until an FBI probe determines the exact nature of his “secret contacts” with Russian officials. The congresswoman also said Flynn should have his security clearance revoked.

According to a recent Washington Post report, Flynn held private discussions with Sergey Kislyak, the Russian ambassador, before Trump took office, promising that sanctions against Moscow would be eased by the incoming administration.

Flynn and Vice President Mike Pence had said that the phone calls were not related to sanctions. Flynn recently backtracked on that claim, saying he had “no recollection” of the details of the conversation.

Washington imposed fresh sanctions on Moscow in December after U.S. intelligence agencies determined that the Kremlin had orchestrated the hacking of Democratic Party emails ahead of the U.S. presidential election.

Any talk of sanctions before Trump took office could put Flynn in violation of the Logan Act, which bars private citizens from negotiating with foreign governments.

In a statement, Pelosi called the reports linking Flynn to Russia emblematic of the “mortifying coziness the Trump Administration has shown with [Russian President Vladimir] Putin.”

“Once again, I am calling on the FBI to investigate the financial, political and personal ties between President Donald Trump and Russia,” she said.

“The American people deserve the truth. President Trump’s kowtowing to Vladimir Putin is endangering our national security and emboldening a dangerous tyrant. What do the Russians have on President Trump that he would flirt with lifting sanctions and weakening NATO?”

Pelosi’s call to suspend Flynn follows similar demands by other leading Democrats, notably Rep. Adam Schiff (D-Calif.), the ranking member on the House Intelligence Committee, who said Flynn should be fired if the report was true.