GOP Sen. Susan Collins Susan Margaret CollinsThe Hill's Campaign Report: Biden asks if public can trust vaccine from Trump ahead of Election Day | Oklahoma health officials raised red flags before Trump rally Gideon leads Collins by 12 points in Maine Senate race: poll Senate leaders quash talk of rank-and-file COVID-19 deal MORE (Maine) says she is concerned by reports President Trump’s national security adviser discussed sanctions with Russia’s ambassador before he entered office, saying Michael Flynn's job could be in danger if he lied.

“That would be inappropriate and troubling,” Collins told CNN Monday when asked about claims Flynn had misled others about the content of his conversations with Sergey Kislyak.

“It would be very difficult for me to continue to rely on someone in such a vital position [if Flynn] had not been truthful,” Collins added of the retired Army general.

ADVERTISEMENT

Flynn reportedly has neither plans to resign from his post nor fears that he will be fired amid growing scrutiny of his discussions with the Russian ambassador in December.

“The knives are out,” a senior administration official said of the talks. "There’s a lot of unhappiness about this.”

Reports emerged last week that Flynn and Kislyak discussed U.S. sanctions against Russia during a series of phone calls the month before Trump took office.

Current and former U.S. officials confirmed the pair’s discussion, contradicting Flynn’s public claim he never broached the subject with Kislyak.

Two U.S. officials told The Washington Post Feb. 9 that Flynn led Kislyak to believe that sanctions against Russia would be reevaluated once Trump took office.

“Kislyak was left with the impression that the sanctions would be revisited at a later time,” one said.

The Obama administration imposed fresh sanctions against Russia in December following revelations it interfered in the 2016 presidential race with the goal of helping Trump.

House Minority Leader Nancy Pelosi (D-Calif.) on Monday urged Trump to fire Flynn over the reported phone calls.

“Michael Flynn’s conduct was alarming enough before his secret communications with the Russians were exposed,” she said in a statement.

“Now, we have a National Security Adviser who cannot be trusted to put [Russian President Vladimir] Putin before America. National security demands that General Flynn be fired immediately."