President-elect Donald Trump has nominated a handful of House Republicans to fill key roles in his incoming administration, but those nominees will have to resign their current seats in Congress before they can begin serving in their new positions.

One of those is Rep. Mike Waltz (R-FL), Trump's pick to be the next national security advisor, and it was just revealed that he will resign from his congressional seat on the same day that Trump is inaugurated, January 20, according to the Washington Examiner.

The resignation news prompted the state of Florida to react quickly in announcing that a special election to fill the vacancy left by Waltz was scheduled for April 1.

Rep. Waltz resigns, effective Jan. 20

On Nov. 12, one week after Election Day, President-elect Trump announced in a Truth Social post his selection of Rep. Waltz, a retired U.S. Army Special Forces Green Beret and decorated combat veteran, to be his national security advisor.

In response, Waltz posted on X that he was "deeply honored" to accept Trump's nomination, optimistic about the nation's future, and added, "To my constituents in Florida, thank you. It was an honor to fight for you in Washington and Florida will always be home."

The rumors and speculation about when Waltz would resign from Congress to assume his new role began almost immediately, and The Hill reported on Monday that it had confirmed that the congressman formally submitted his letter of resignation on Monday, to take effect on Jan. 20 next year.

Waltz's impending departure from Congress will further reduce the already slim majority the GOP will have in the House and open up a vacancy for at least a few months, though it is notable that he isn't leaving until after the next session of Congress begins and key early votes, such as for the House Speaker, are dispensed with.

Florida's special elections scheduled for April 1

On Monday, Florida Secretary of State Cord Byrd wrote in an X post, "We are just now in receipt of Congressman Mike Walz's resignation letter, therefore the special election for CD 6 will proceed according to the following timeline."

That timeline includes a special primary election on Jan. 28 followed by the special election itself on April 1 to fill the soon-to-be-vacant seat in Florida's 6th Congressional District.

On Friday, a similar schedule was revealed in a press release for Florida's 1st Congressional District, which was vacated by the immediate resignation of former Rep. Matt Gaetz (R-FL) after he was nominated to serve as attorney general, though he later withdrew himself from consideration for that position amid an outcry of opposition from Democrats, the media, and even some Republicans.

In a statement that accompanied both announcements, Sec. Byrd said, "At Governor Ron DeSantis’ direction, this Special Election is being conducted as quickly as statutorily possible. We are committed to ensuring this election is held as soon as we are allowed to hold it by state law."

House GOP's slim majority shrinks further with vacancies

The Hill noted that in addition to the vacancies caused by the resignations of Reps. Waltz and Gaetz, House Republicans will also be short one more member once Rep. Elise Stefanik (R-NY) resigns her seat to accept President-elect Trump's nomination of her to be the next U.S. ambassador to the United Nations.

It remains unclear at this time when Stefanik will leave her seat or when New York will hold a special election to fill that vacancy, but like the two districts in Florida, her upstate New York district is considered safe territory for the GOP and will likely continue to be in the Republican column once voters have had their say.

However, for at least a couple of months until their successors have been chosen, House Republicans will have virtually no margin for defections as they only hold the majority by a handful of seats.