West Virginia Attorney General Patrick Morrisey will formally kick off his bid for the Senate Monday, setting up a fight to unseat Democratic Sen. Joe Manchin in the coal mining state.

National Review first reported that Morrisey, a Republican, will be announcing his Senate run on Monday afternoon. The attorney general said on Twitter he would be making a "major announcement" at the Clarion Hotel in Harpers Ferry at 5 p.m., but gave no details on what exactly he would be announcing.

A source close to the attorney general confirmed that it would be to launch his race for the U.S. Senate.

An election video he later put up said, "Morrisey's got grit. He knows how to get things done and what makes our country great."

"We need someone who is going to take on Washington corruption and advance conservative values. There is so much we can do if we have a conservative with principles going to Washington. And someone who is willing to take on the mess," Morrisey said in the video. "As your senator, I'll stand with President Trump and we will beat the Washington elites."

The Mountaineer State supported President Trump in the 2016 election based on his promises to restore coal country and the jobs that had been lost due to strict environmental regulations that favored renewable energy over fossil fuels.

Morrisey helped lead 28 state attorney generals in a major lawsuit to stop the Obama administration's climate regulations, and has been supportive of Trump's deregulation agenda.

In addition to challenging Manchin, Morrisey will also see competition from Republicans, namely Rep. Evan Jenkins and laid-off coal miner Bo Copley, who announced his bid earlier this year.

Copley had told Hillary Clinton during the 2016 election race that miners "don't see you as a friend."