Republican Party chairwoman Ronna McDaniel said on Monday she was leaving the job, after weeks of public pressure from the party's likely 2024 presidential candidate, Donald Trump.
The move came after former US president Trump, the frontrunner for the party's presidential nomination, indicated he wanted to make changes to the Republican National Committee (RNC) as he prepares for a likely rematch with president Joe Biden, a Democrat, in November.
"The RNC has historically undergone change once we have a nominee, and it has always been my intention to honour that tradition. I remain committed to winning back the White House and electing Republicans up and down the ballot in November," Ms McDaniel said in a statement.
She thanked Mr Trump and said the move would be effective March 8th to allow the Republican nominee to choose the chair.
Fifteen states and one US territory will hold Republican nominating contests on Super Tuesday, which falls on March 5th this year.
RNC co-chair Drew McKissick also said he would step down.
Two weeks ago, Mr Trump endorsed North Carolina Republican Party chair Michael Whatley as the next RNC chair and his daughter-in-law Lara Trump as co-chair, moving to cement his grip over the organisation as he closed in on the 2024 presidential nomination.
Whoever replaces Ms McDaniel will face the challenge of unifying a fractured party with just nine months to go before the 2024 election.
The RNC plays a critical role in raising money for the nominee, promoting the party's message, marshalling resources and turning out voters.
After a meeting with Ms McDaniel early this month, Mr Trump wrote on social media that he would be pushing for changes at the RNC after South Carolina's February 24th primary, which he won handily on Saturday.
Mr Trump, shortly after he won the 2016 election, had endorsed Ms McDaniel - the niece of his former critic and 2012 Republican presidential nominee Mitt Romney - to take over the RNC.
Ms McDaniel helped Mr Trump win Michigan in that election, a state that was critical to Mr Trump's victory over Democrat Hillary Clinton.
Ms McDaniel, who used her full name Ronna Romney McDaniel in public life, dropped the middle name after that endorsement. Multiple news outlets reported that Mr Trump asked her to do so.
Mitt Romney, now a US senator from Massachusetts, denounced Mr Trump as a "phoney, a fraud" in an unusual March 2016 speech in which he urged Republicans to reject their own frontrunner.
