"My guilty plea and agreement to co-operate with the Special Counsel's Office reflect a decision I made in the best interests of my family and of our country".
He added that his actions "were wrong, and, through my faith in God, I am working to set things right".
Flynn rejected claims that he had committed treason, but said he accepts "full responsibility for his actions." .
Flynn's plea, Warner said, "comes on the heels of a new report about the President's efforts to silence the independent, bipartisan Senate investigation into ties between Trump associates and Russian Federation".
Special Counsel Robert Mueller has charged Flynn with "willfully and knowingly" making "false, fictitious and fraudulent statements" to the agency about his conversations with Russia's ambassador, Sergey Kislyak.
A "very senior member" of Trump's transition told Flynn on December 22 to contact officials from Russian Federation and other foreign governments about how they would vote and "to influence those governments to delay the vote or defeat the resolution", the statement of offense said.
Warner, the ranking member on the Senate Intelligence Committee, was asked whether he believes Flynn will implicate President Trump. His bombshell admission that he coordinated his calls with Kislyak with a senior transition official raises the specter that Mueller could bring charges against other current or former administration officials.
Michael Flynn is ready to spill the beans on Trump, according to Ross. Flynn also denied receiving a response to the request.
The charges against Flynn relate to a series of discussions the general had last December, during the presidential transition, when he reportedly told Kislyak that Trump's White House might go easy on sanctions against Russian Federation that were imposed by President Obama and asked Kislyak to sabotage a United Nations resolution on Israel that Obama's White House supported.
Warner noted that it's the second Trump campaign associate to plead guilty to making false statements, while former campaign chairman Paul Manafort and his deputy are facing a slew of charges.
The Obama administration, in a rare step that shocked its Middle East ally, planned to abstain on the motion rather than veto it as had been done in the past.
On the same day Mueller's office announced the indictments of Manafort and Gates, it was revealed that George Papadopoulos, a 30-year-old former Trump adviser, had pleaded guilty to lying to the Federal Bureau of Investigation about his contacts with Russian Federation. "It was about the 35 guys who were thrown out", Flynn told the Daily Caller at the time.
A White House lawyer said that nothing in Flynn's guilty plea "implicates anyone other than Mr Flynn".
The White House, which has long denied any wrongdoing in relation to Moscow, said Flynn's false statements "mirror the false statements to White House officials which resulted in his resignation in February of this year".
The opposition Democratic Party was quick to slam Trump. He has been under investigation for a wide range of allegations, including lobbying work on behalf of Turkey, but the fact that he was charged only with a single count of false statements suggests he is cooperating with Mueller in exchange for leniency.
But Trump has repeatedly rejected that view.
Former Trump campaign chairman Paul Manafort surrendered to federal authorities on October 30 after he was indicted, along with his business associate Rick Gates, on 12 counts, including conspiracy against the U.S. and money laundering.