Story highlights Trump's tweet raised immediate questions about whether he knew Flynn had lied to the FBI when he fired him in February 
 
 His tweet has started garnering reaction 
 
 Washington (CNN) President Donald Trump said Saturday that he is not worried about what his former national security adviser, Michael Flynn, might tell special counsel Robert Mueller's team as it investigates Russia's efforts to influence last year's election. 
 
 When asked by reporters if he was worried about what Flynn might say, Trump replied, "No, I'm not. And what has been shown is no collusion, no collusion. There has been absolutely no collusion. So we're very happy." 
 
 Flynn pleaded guilty Friday to lying to the FBI about conversations with Russia's ambassador and disclosed that he is cooperating with the special counsel's office. 
 
 Trump made his brief comments about Flynn's plea deal before flying to New York for a fund-raiser later Saturday, although he spent most of his time touting the Republican tax plan, which he continued to sell as "the biggest tax cut in the history of our nation." 
 
 The President expanded on his thoughts on Flynn as he left the fund-raising event, tweeting: "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!" 
 
 Read More ||||| U.S. President Donald Trump defended his disgraced former national security adviser Michael Flynn on Saturday, saying that the basis of a special prosecutor's actions against the former general were "lawful" and above board — even as he acknowledged Flynn had lied to federal officials. 
 
 Earlier, Trump told reporters that there was "no collusion" with Russia, in spite of Flynn entering a guilty plea on Friday for having lied to the FBI about discussions he held with a Russian ambassador. The president added that he was "very happy" about the developments, while reiterating there had been no coordination between his campaign and Moscow. 
 
 However, Trump later tweeted that he was forced to fire Flynn for lying to both Vice President Mike Pence and federal investigators, adding that Flynn's discussions were "nothing to hide." If accurate, it is still unclear why Flynn felt compelled to make a false statement in the first place. 
 
 Friday's report by ABC, which has now been corrected by the news outlet, suggested that Flynn was prepared to testify that he was directed by Trump to make overtures to a Russian diplomat. The initial report sparked a media firestorm that was quelled only after ABC clarified that Flynn's actions had occurred during the transition. 
 
 Months of probing by special prosecutor Robert Mueller culminated in Flynn's guilty plea, which came days after it emerged that the former general's legal team had stopped cooperating with Trump's lawyers. Still, there appeared to be little immediate evidence that the Trump campaign made any efforts to collaborate with Russia's suspected attempts to influence the general election. 
 
 Flynn's plea, combined with the recent indictment of former campaign chair Paul Manafort, has underscored a convoluted web of who said what to whom and when. 
 
 Ultimately, however, the case is mostly characterized by what an Associated Press report on Saturday referred to "lots of smoke, but no smoking gun." Even the president's sharpest detractors have been unable to find concrete evidence that his campaign may have coordinated with, or was even aware of, Russian efforts to swing the election. 
 
 Even Leon Panetta, former president Barack Obama's Secretary of Defense and a veteran of the Clinton administration, acknowledged that anyone trying to find criminality with the Trump transition team speaking to the Russians would be reaching. 
 
 Panetta told MSNBC on Friday that it was a "stretch" to say transition officials broke the law, even though the Obama administration still held the reins of government at the time. ||||| Tweet with a location 
 
 You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more ||||| President Trump commented Saturday on his former national security adviser Michael Flynn's guilty plea, saying there was "nothing to hide" about Flynn's actions during the presidential transition. 
 
 "I had to fire General Flynn because he lied to the Vice President and the FBI. He has pled guilty to those lies," Trump wrote in a tweet. 
 
 "It is a shame because his actions during the transition were lawful. There was nothing to hide!" he added. 
 
 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 
 
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 Trump's tweets come a day after Flynn pleaded guilty to lying to the FBI, part of special counsel Robert Mueller's probe into Trump campaign associates' ties to Russia. 
 
 Flynn acknowledged to investigators that he had spoken with then-Russian Ambassador to the U.S. Sergey Kislyak in the month before Trump took office about U.S. sanctions, despite his previous comments. 
 
 Prosecutors also said that Flynn was directed by a "very senior member" of the Trump transition team to contact officials from Russia and other countries to push them to vote against a United Nations Security Council resolution. 
 
 Multiple reports on Friday indicated that Trump's son-in-law and senior adviser Jared Kushner was that senior transition official. 
 
 Flynn was ousted as Trump's national security adviser on Feb. 13, just 24 days after entering the administration. 
 
 In June, Former FBI Director James Comey testified before the Senate that Trump asked him during a Feb. 14 meeting to "let go" of an investigation into Flynn. 
 
 Flynn's guilty plea represents a major milestone in Mueller's probe into alleged collusion between the Trump campaign and Russian officials during the 2016 campaign. 
 
 The retired general is the first person who held a Trump administration position to be brought down by Mueller and his team of investigators. 
 
 Mueller announced last month former Trump campaign chairman Paul Manafort and his business associate Richard Gates were indicted on charges of conspiracy against the U.S. and money laundering. 
 
 Former Trump campaign foreign policy adviser George Papadopoulos also pleaded guilty to lying to FBI investigators. 
 
 Updated: 1:39 p.m.
– On Saturday, President Trump weighed in to reporters and on Twitter on Michael Flynn's guilty plea. Trump said that—in the wake of news Flynn is cooperating with Robert Mueller's investigation—he's not worried what his former national security adviser might disclose, CNN reports. "What has been shown is no collusion, no collusion," Trump told reporters. "There has been absolutely no collusion. So we're very happy." He later tweeted: "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!" But Trump's comments are raising questions. Flynn pleaded guilty Friday to lying to the FBI about conversations he had with former Russian ambassador Sergey Kislyak. The Hill reports Flynn was removed from the Trump administration Feb. 13. Former FBI director James Comey later testified that Trump asked him to "let go" of the investigation into Flynn the following day. Trump's tweet seems to imply Trump knew Flynn lied to the FBI when he fired him. Democratic Rep. Ted Lieu says that would constitute obstruction of justice. CNBC notes it's also unclear why Flynn would have lied to the FBI in the first place if, as Trump claims in his tweet, Flynn's actions "were lawful" and "there was nothing to hide."