Former President Barack Obama warned then-President-elect Donald Trump not to give the post of national security adviser in his administration to Michael Flynn, according to a former Obama aide.

Flynn was eventually fired due to his alleged ties to Russia, and the fact that he wasn't completely honest with Vice President Mike Pence about his meeting with the Russian ambassador.

At a press briefing on Monday, White House Press Secretary Sean Spicer acknowledged that Obama made it known that "he wasn't exactly a fan" of Flynn's.

Spicer said it wasn't clear if Obama felt that way because he actually mistrusted Flynn or because Flynn was a prominent critic of both Obama and Democratic nominee Hillary Clinton during the 2016 campaign.

"The question you have to ask yourself is: If President Obama was truly concerned about Gen. Flynn, why didn't he suspend Gen. Flynn's security clearance, which they had just re-approved months earlier?" Spicer said.

He added this also makes one wonder why the Obama administration would let Flynn go to Russia and receive payment for a speech if they were concerned.

"There were steps that they could have taken if that was truly a concern, more than a person that had bad blood," Spicer said.

Watch more above.

Dem Senator Drops F-Bomb While Criticizing Republicans, AHCA

Sheriff Shaq?! Former NBA Star Plans to Run in 2020

Columnist: Hillary's Excuses for Election Loss Point to One Thing – a 2020 Run

Texas Gov. Abbott Signs Bill That 'Effectively Bans' Sanctuary Cities