Updated

West Virginia Gov. Joe Manchin announced on Tuesday his plans for a U.S. Senate bid this fall.

The governor said during a press conference with reporters that he'll run for the seat held by the late Robert C. Byrd.

"I only hope I would be able to follow in his footsteps and continue to help the people of West Virginia," Manchin said of Byrd, who died last month at age 92.

"I intend, with the opportunity, to work as hard in Washington as I've worked in West Virginia," he said. "I believe in you more than you believe in yourself."

Manchin, a Democrat, announced his plans following passage of special session legislation setting an Aug. 28 primary and Nov. 2 general election for the seat.

The winner of that election will take over from Carte Goodwin, Manchin's temporary appointee to the seat. The 36-year-old former chief counsel takes his oath of office Tuesday.

Manchin has been governor since 2005, and won his second term by the largest margin for that office in the state's history. The 62-year-old became chairman of the influential National Governors Association this month.

Manchin, who briefed his cabinet and staff during a closed-door meeting in advance of his morning announcement, has won praise from such groups as the Cato Institute for his conservative approach to state finances and his push for gradual tax cuts benefiting both businesses and consumers.

Manchin's candidacy was met with criticism from the GOP. In a statement released on Tuesday, Republican National Committee chairman Michael Steele called Manchin "nothing but a lap dog and rubber stamp for President Obama's liberal tax, spend and borrow policies.

"Gov. Manchin's liberal record and ties to the Washington elite have politicians like President Obama and Harry Reid dancing for joy, but people in West Virginia will feel the brunt of their misguided policies," he said.

Republicans view their top prospect as Rep. Shelley Moore Capito, R-W.Va. State GOP lawmakers won an amendment in the legislation that allows her to seek Byrd's seat without abandoning her bid for a sixth U.S. House term.

The Associated Press contributed to this report