Sen. Marco Rubio, R-Fla., endorsed former President Trump on Sunday instead of his state's governor, Ron DeSantis, for the 2024 presidential election.

"When Trump was in WH I achieved major policies I had worked on for years (like expanded Child Tax Credit & tough sanctions on regime in Cuba & Venezuela) because we had a President who didn’t cave to special interests or let bureaucrats block us," Rubio wrote on X.

"I support Trump because that kind of leadership is the ONLY way we will get the extraordinary actions needed to fix the disaster Biden has created," he added. "It’s time to get on with the work of beating Biden & saving America!"

TRUMP PICKS UP MORE SENATE GOP ENDORSEMENTS

Rubio had contested against Trump in the 2016 election but withdrew from the race following his defeat in the Florida primary. Last November, Florida Sen. Rick Scott threw his support behind Trump, leading both state senators to favor Trump over DeSantis.

During the contentious 2016 race, Trump often referred to Rubio as "Little Marco," while Rubio referred to Trump as a "con artist" and said his administration would be "chaos." 

TRUMP TAKES NO CHANCES AS THE IOWA CAUCUSES APPROACH

Just hours before Rubio threw his support behind Trump, North Dakota Gov. Doug Burgum — who also dropped out of the 2024 race — endorsed the former president as well.

Rubio's endorsement comes as Trump remains the consistent frontrunner in surveys. He joins nearly two dozen GOP senators in endorsing Trump, including Sens. JD Vance of Ohio, Marsha Blackburn of Tennessee, Rick Scott of Florida, Josh Hawley and Eric Schmitt of Missouri, Tom Cotton of Arkansas, Lindsey Graham of South Carolina, and others.

Iowa caucusgoers will cast their vote for the Republican presidential nominee Monday evening. 

Fox News' Paul Steinhauser contributed to this report.