President Trump spoke publicly Saturday morning for the first time since his former national security adviser Michael Flynn pleaded guilty to lying to the FBI on Friday, saying he "had to fire" Flynn because he lied to Vice President Mike Pence and the FBI.

Flynn misled Pence about his contact with then-Russian Ambassador Sergey Kislyak, and later, lied to the FBI about that contact in a Jan. 24 interview, as he pleaded guilty in federal court on Friday. But the president's tweet Saturday president raises the question of whether he was aware Flynn lied to the FBI before firing him on Feb. 13. Mr. Trump insisted, "There was nothing to hide!"

Former FBI Director James Comey has said that the president asked him to drop the investigation into Flynn the day after Flynn was ousted, on Feb. 14.

I had to fire General Flynn because he lied to the Vice President and the FBI. He has pled guilty to those lies. It is a shame because his actions during the transition were lawful. There was nothing to hide! — Donald J. Trump (@realDonaldTrump) December 2, 2017

On Saturday, Mr. Trump, asked whether the Flynn guilty plea worried him Saturday morning, emphasized there was "no collusion."

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"What has been shown is no collusion, no collusion," Mr. Trump said, responding to a reporter's question about whether the Flynn plea worries him before pivoting to a major tax bill the Senate passed just before 2 a.m. Saturday. "There's been absolutely no collusion, so we're very happy. And frankly last night was one of the big nights."

"We'll see what happens," added the president, who is on his way to New York for a series of fundraisers.

On Saturday night, Mr. Trump followed up with another tweet on Flynn, writing "so General Flynn lies to the FBI and his life is destroyed, while Crooked Hillary Clinton, on that now famous FBI holiday 'interrogation' with no swearing in and no recording, lies many times...and nothing happens to her?"

So General Flynn lies to the FBI and his life is destroyed, while Crooked Hillary Clinton, on that now famous FBI holiday “interrogation” with no swearing in and no recording, lies many times...and nothing happens to her? Rigged system, or just a double standard? — Donald J. Trump (@realDonaldTrump) December 3, 2017

He posted another tweet a few minutes later referencing Clinton's email server.

Many people in our Country are asking what the “Justice” Department is going to do about the fact that totally Crooked Hillary, AFTER receiving a subpoena from the United States Congress, deleted and “acid washed” 33,000 Emails? No justice! — Donald J. Trump (@realDonaldTrump) December 3, 2017

Prosecutors in Flynn's case indicated that other high-level Trump associates were at least aware of Flynn's contacts with the Russian ambassador Sergey Kislyak.

CBS News Chief White House correspondent Major Garrett reports sources with knowledge of the situation say top White House aide Jared Kushner was the "very senior" official who spoke with Flynn on Dec. 22 of last year about a pending U.N. Security Council debate vote on Israeli settlements. The sources with knowledge of the situation also told CBS News that K.T. McFarland was the "senior official" on the Presidential Transition Team (PTT) who spoke to Flynn in Mar-a-Lago on Dec. 29 about Russian sanctions and possible Russian retaliation.

These contacts are potentially meaningful if they can be linked to behavior that is criminal or conspiratorial. But no evidence has yet surfaced to indicate either criminality or a conspiracy.

A document filed with the court by the special counsel says that Flynn "did willfully and knowingly make materially false, fictitious and fraudulent statements and representations" to the FBI regarding his interaction with then-Russian Envoy Sergey Kislyak. In early December, after the election, he Kushner met with Kislyak at Trump Tower. On Dec. 29, Flynn called Kislyak five times, and the two spoke about sanctions against Russia that had just been imposed by President Obama in response to Russia's meddling in the 2016 U.S. elections.

According to court documents released Friday, a "very senior member" of the Trump transition team -- Kushner -- directed Flynn to contact Russia and officials from other foreign governments in December 2016 to determine where they stood on an Israeli settlement U.N. resolution.

"On or about December 22, 2016, a very senior member of the Presidential Transition Team directed FLYNN to contact officials from foreign governments, including Russia, to learn where each government stood on the resolution and to influence those governments to delay the vote or defeat the resolution," the statement of offense against Flynn reads.

The White House has distanced itself from Flynn, who Mr. Trump once called a "wonderful man."

Ty Cobb, a White House lawyer, said in a statement that Flynn is a "former Obama administration official."

"Today, Michael Flynn, a former national security advisor at the White House for 25 days during the Trump administration, and a former Obama administration official, entered a guilty plea to a single count of making a false statement to the FBI," Cobb said in a statement.

"The false statements involved mirror the false statements to White House officials which resulted in his resignation in February of this year. Nothing about the guilty plea or the charge implicates anyone other than Mr. Flynn," Cobb said. "The conclusion of this phase of the Special Counsel's work demonstrates again that the Special Counsel is moving with all deliberate speed and clears the way for a prompt and reasonable conclusion."

CBS News' Kathryn Watson contributed to this report.