In a setback to President Donald Trump, his former national security advisor Michael Flynn today pleaded guilty to making false statements to the FBI over possible collusion between the Trump campaign and Russia during last year's US presidential polls.
Flynn appeared before a federal court this morning to plead guilty after ex-FBI director Robert Mueller, who is investigating allegations of Russian interference in the presidential election as a special counsel, announced that Flynn was charged with "wilfully and knowingly" making "false, fictitious and fraudulent statements" to the Federal Bureau of Investigation about his conversations with Russia's then ambassador to the US Sergey Kislyak.
The Washington Post described it as "another monumental development" in Mueller's wide-ranging probe.
There was no immediate reaction from the White House.
As per the charge sheet, 58-year-old Flynn, a retired general, lied when he told investigators that he did not ask Kislyak to "refrain from escalating the situation" in response to sanctions that then-president Barack Obama had imposed on Russia, and that he did not ask the ambassador to either delay or defeat a related UN Security Council vote.
Flynn is the first Trump administration official and the fourth connected to the campaign to be charged as part of an investigation into possible collusion between the Russian government and members of Trump's team, as well as potential obstruction of justice and financial crimes.
Trump's former campaign chairman Paul Manafort and his deputy Rick Gates were indicted last month. They pleaded not guilty.
The Trump campaign's foreign policy adviser George Papadopoulos had also pleaded guilty for lying to the FBI over contacts with officials connected to the Russian government.
The charge against Flynn is the first in Mueller's probe that has reached someone in the Trump White House and is the latest sign that the special counsel's investigation is intensifying, CNN reported.
A key campaign adviser during Trump's presidential campaign, Flynn was tapped as Trump's national security adviser in November, 2016, a senior White House job that put him in a vital role for all of the administration's national security and foreign policy decisions.
But he resigned from the post soon after it emerged that he had misled Vice President Mike Pence and then-chief of staff Reince Priebus about his conversations with Kislyak in which they discussed US sanctions against Russia.
"The development came at a particularly sensitive moment for the White House, just as Mr Trump and Republican congressional leaders are toiling to hold together a tenuous coalition to push through a large tax cut plan," the New York Times said.
The opposition Democratic Party was quick to slam Trump.
"This time, the president can't get away with claiming these charges aren't about his inner circle's contacts with Russia, and he can't dismiss Michael Flynn as some low-level aide.
"This development should serve as a clear signal to Republicans in Congress that it is time to take this investigation seriously and stop making excuses for the president's attempts to interfere with it," said Democratic National Committee chair Tom Perez.
"Democrats will not stand by as Trump's enablers in Congress betray the American people, undermine our democracy, and endanger our national security. It's time for Republicans to commit to protecting this investigation and preserving the rule of law," he said.