President Trump reiterated Saturday morning that “no collusion” occurred between Russia and his 2016 presidential campaign, in his first public comments since former National Security Adviser Michael Flynn pleaded guilty in a federal investigation into possible collusion between Moscow and Trump associates.

“No collusion,” Trump said in brief comments from the White House South Lawn before departing for New York. “There was absolutely no collusion. So we are very happy.”

Flynn, a retired general, pleaded guilty Friday to lying to the FBI about reaching out to the Russians on Trump's behalf and said members of the president's inner circle were intimately involved with -- and at times directing -- his contacts.

His plea to a single felony count of false statements made him the first official of the Trump White House to be charged so far in the criminal investigation by special counsel Robert Mueller.

The plea turns Flynn into a potentially key government cooperator as prosecutors examine whether the Trump campaign and Russia worked together to influence the election in Trump's favor.

Friday's developments don't resolve the paramount question of possible Trump-Russia coordination in the campaign, but they do show that Flynn lied to the FBI about multiple conversations last December with the Russian ambassador to the United States.

Court papers make it clear that senior Trump transition officials were fully aware of Flynn's outreach to Russian officials in the weeks before the inauguration.

The officials were not named in court papers, but people familiar with the case identified two of them to The Associated Press as Jared Kushner, the president's son-in-law, and former Deputy National Security Adviser KT McFarland, now up for an ambassadorship.

The Associated Press contributed to this report.