House Speaker Mike Johnson is heading to former President Donald Trump's Mar-a-Lago resort for a joint appearance on Friday as he tries to shore up conservative support and fend off a threat to his speakership led by GOP Rep. Marjorie Taylor Greene of Georgia.

Greene has threatened to force a vote to oust Johnson over government spending and aid to Ukraine, although no other House Republicans have signed on to the effort. Johnson was narrowly elected after multiple other candidates failed to secure the gavel last year, and Republicans have an even narrower margin in the House now. A single member can force a vote to oust a speaker, a rule former House Speaker Kevin McCarthy agreed to in order to capture his short-lived speakership.

Johnson and Trump are set to deliver remarks Friday afternoon from Mar-a-Lago about "election integrity." Trump continues to falsely claim that he lost the 2020 election due to voter fraud.

At the Capitol on Friday, Johnson wouldn't tell reporters whether he will bring up Greene's efforts in his conversation with Trump. 

"I don't ever comment on my private conversations with President Trump, but I'm looking forward to going to Florida and spending some time with him," Johnson said. 

He hinted at the "election integrity" legislation that the two are expected to discuss. 

"Congress has a role with regard to federal elections. We want to make absolutely certain that anybody who votes is actually an American citizen. In some states, it's too easy. You just check a box and, and you can vote. So we need to make sure that federal law is clear on that matter," Johnson said. He was responding to a question about the necessity of new legislation, since federal law already prohibits non-citizens from voting in federal elections. A database maintained by the Trump-aligned Heritage Foundation shows just 25 cases of non-citizens trying to vote in federal elections in the last 20 years.

The Biden campaign released a statement from Rep. Bennie Thompson, the chair of the House committee that investigated the Jan. 6 attack on the Capitol, calling Trump "a threat to our democracy and a danger to our Constitution."

"Donald Trump and Mike Johnson don't care about election integrity — they care only about helping Trump's campaign of revenge and retribution to regain power at all costs," Thompson said.

Back in Washington, Greene has not said when she might force a vote on Johnson's removal. Her opposition comes as Johnson faces mounting pressure to call a vote on approving more aid for Ukraine, something Greene strongly opposes. Greene renewed her threat in a letter this week.

Johnson told the Christian Broadcasting Network earlier this week that he doesn't "harbor any ill will towards Marjorie," but said a stalemate in Congress is counterproductive to the Republican Party and Trump's chances in 2024. The House ground to a halt for weeks after McCarthy's ouster in the fall.

"We've got to demonstrate the American people that we can keep the train on the tracks," he told CBN. "And so pulling a motion to vacate, removing the speaker right now is exactly the opposite of what we need to show the country. We can't close the Congress down, because that's what will happen. They will blame us. And so it would hurt our chances of growing the majority, or our party or President Trump's chances for his election because all of our fates in, in some sense, are tied together."

Johnson's venture to Mar-a-Lago is reminiscent of McCarthy's visit to Mar-a-Lago weeks after Trump supporters assaulted the Capitol on Jan. 6, 2021, endangering members of Congress and Vice President Mike Pence. McCarthy initially blamed Trump for the riot, but needed Trump's support to eventually become speaker.

Jaala Brown, Scott MacFarlane and Caitlin Yilek contributed to this report.