Washington CNN  — 

Democratic Gov. Jim Justice of West Virginia announced his plans to change his political party affiliation and join the GOP at a rally in Huntington with President Donald Trump on Thursday night.

“Today I will tell you as West Virginians, I can’t help you anymore being a Democrat governor,” Justice said at the rally. “So tomorrow, I will be changing my registration to Republican.”

The New York Times first reported Justice’s plans to switch parties.

Earlier Thursday, Trump teased that there would be a “very big announcement” this evening in West Virginia, a state that went heavily Republican in the 2016 elections.

West Virginia Sen. Joe Manchin released a statement in response to Justice’s announcement on Thursday evening. “I have been and always will be a proud West Virginia Democrat,” Manchin said. “I am disappointed by Gov. Justice’s decision to switch parties. While I do not agree with his decision, I have always said that I will work with anyone, no matter their political affiliation, to do what is best for the people of West Virginia.”

Manchin is up for re-election in 2018. With Justice’s move, Manchin will become West Virginia’s only statewide elected Democrat besides treasurer John Perdue.

This isn’t the first time Justice has switched parties – he was previously an independent and a Republican up until 2015 when he ran for governor as a Democrat. However, this move could indicate a bigger shift in the state.

In Justice’s latest State of the State address, the governor mentioned Trump five times, and said he was good friends with the Trump family.

If Justice moves across the aisle as reported, it would increase the advantage of Republican governors over Democrats to 34 to 15.

CORRECTION: This story has been updated to note that West Virginia treasurer John Perdue is a Democrat who was also elected statewide.

CNN’s Lauren Fox, Ashley Killough, Tal Kopan and Wade Payson-Denney contributed to this report.