House Oversight and Government Reform Committee Chairman Jason Chaffetz, R-Utah, threatened to use his subpoena power to obtain a memo from former FBI Director James Comey that said President Trump pressured him to drop a probe into ousted national security adviser Mike Flynn.

Chaffetz announced on Twitter that his panel will obtain the memo, one way or another.

"GOP oversight is going to get the Comey memo, if it exists." Chaffetz tweeted. "I need to see it sooner rather than later. I have my subpoena pen ready."

That move was backed by House Speaker Paul Ryan's office. "We need to have all the facts, and it is appropriate for the House Oversight Committee to request this memo," said AshLee Strong, a spokesperson for Ryan.

Chaffetz also released a letter to Acting FBI Director Andrew McCabe that said the Times' report said Comey created other memos that need to be assessed to determine whether Trump improperly tried to influence Comey.

"So the committee can consider that question, and others, provide, no later than May 24, 2017, all memoranda, notes, summaries, and recordings referring or relating to any communication between Comey and the president," he wrote.

Republicans are particularly interested to see the memo referenced in the Times story, in which Comey recalls Trump telling him "I hope you can let this go," after Trump fired Flynn over his pre-inaugural phone call with Russian officials about Obama-administration sanctions.

Chaffetz told NBC Tuesday the panel "is drafting the necessary paperwork to get the memo so we will find out in a hurry if it's out there."

In the interview, Chaffetz said he has not seen the memo but based on the New York Times story "it seems like an extraordinary use of influence to try to shut down an investigation being done by the FBI."

Chaffetz added, "I'll use every tool we have" to obtain the memo.