The resolution unanimously approved by the RNC at its winter meeting in New Mexico offered "undivided support for President Donald J. Trump and his effective Presidency."
While the resolution is largely symbolic, it is also unusual, because the RNC has historically refrained from expressing support for a candidate before he officially becomes the party's nominee.
The vote on Friday signals how the Republican Party has come to fully embrace Trump, three years after many Republican officials and members dismissed him as a thorn in the GOP's side.
The vote isn't the only sign of the party's deepening ties to Trump. The president's campaign committee is expected to merge its field and fundraising operations with the RNC for the reelection bid, creating a single entity intended to streamline campaign efforts.