Besides threatening to cancel White House press briefings and giving fired FBI Director James Comey a warning that there might be "tapes" of their conversations that exist, the president also glommed on to remarks made by former Director of National Intelligence James Clapper to call the Russian Federation investigations a "witch hunt".
It was the committee's first subpoena in the Russian investigation.
Flynn, as the most senior of the four, became the focal point of concern about alleged Russian interference after it emerged he secretly discussed U.S. sanctions with Sergey Kislyak, the Russian ambassador to Washington, in December.
Flynn has come under committee scrutiny over communications he had with Russian Ambassador Sergey Kislyak while a representative of then-President-elect Donald Trump's transition team.
In March, Flynn's lawyer, Robert Kelner, requested "assurances against unfair prosecution" in exchange for Flynn giving testimony to the panel.
In yesterday's interview with NBC News' Lester Holt, Trump added, "This man (Flynn) has served for many years, he's a general, he's a - in my opinion - a very good person". According to multiple accounts in USA media, the latter was the reason behind Trump's stunning firing of Comey on Tuesday.
The subpoena comes a day after President Trump removed James Comey as FBI director during an ongoing investigation into ties between the Trump campaign and Moscow.
He says the former FBI Director James Comey's firing will in no way deter the committee from finding out the truth.
Comey was astonished by Trump's wiretapping claims and told aides, according to The New York Times, it was "outside the realm of normal" and perhaps "crazy".
Committee chairman Republican Richard Burr had previously warned he would issue subpoenas for those who did not cooperate with the investigation.
"I want to get to the bottom if Russian Federation or anybody is trying to tamper or play with our election", Trump told Fox News' Jeanine Pirro.
Flynn has been accused by senior lawmakers on Capitol Hill of violating the law for taking payments from groups associated with foreign governments without first seeking permission, which he was required to do as a retired lieutenant general.