Rep. Trey Gowdy (R-SC) responded this morning to former Obama national security adviser Susan Rice declining an invitation to testify before Congress on the unmasking of Trump team members.

Fox News reported a month ago that Rice requested to unmask the names of Trump transition officials caught up in incidental surveillance.

Trump took to Twitter to call out Rice for refusing Sen. Lindsey Graham's invitation to appear before a Senate Judiciary subcommittee looking into Russia's interference in the 2016 election.

Susan Rice, the former National Security Advisor to President Obama, is refusing to testify before a Senate Subcommittee next week on..... — Donald J. Trump (@realDonaldTrump) May 4, 2017

...allegations of unmasking Trump transition officials. Not good! — Donald J. Trump (@realDonaldTrump) May 4, 2017

Gowdy said a subpoena may have to be used to bring Rice before Congress.

"There are things called subpoenas. You shouldn't have to use it with a former national security adviser but if you do, you do," said Gowdy, calling Rice a "very important witness."

He said Rice may feel like she cannot testify in an open setting, so a closed-door hearing could be scheduled for Rice to give her account.

Responding to FBI Director James Comey's testimony before the Senate yesterday, Gowdy said he does not buy into Hillary Clinton's claim that she lost the election because of Comey's late October letter.

"Someone was gonna criticize him no matter what he did. He did what he thought was right," said Gowdy, adding that Comey didn't tell Clinton to set up a private server or to give "disingenuous answers" about it throughout the campaign.

Watch the "America's Newsroom" interview above.