In a surprise announcement about his political future, Sen. Johnny Isakson (R-GA) said Wednesday that he would resign from the U.S. Senate at the end of this year because of personal health issues, meaning the state of Georgia could have two Senate seats on the ballot in the 2020 elections.

"I am leaving a job I love because my health challenges are taking their toll on me, my family and my staff," Isakson said in a statement issued by his office.

Isakson was diagnosed several years ago with Parkinson's disease, which at times left him in a wheelchair in the halls of the Capitol.

"My Parkinson’s has been progressing, and I am continuing physical therapy to recover from a fall in July," Isakson said. "In addition, this week I had surgery to remove a growth on my kidney."

Georgia Governor Brian Kemp will get to choose an interim replacement, with a likely special election in November 2020 to fill the final two years of his Senate term.

The 74 year old Isakson was first elected to the U.S. House in 1999, replacing ex-House Speaker Newt Gingrich.

In 2004, Isakson won a U.S. Senate seat which opened after the retirement of Zell Miller (D-GA).

Amid signs of health problems several years ago, Isakson acknowledged in June of 2015 that he had been diagnosed with Parkinson's.

He won re-election in 2016.

“Johnny is a leader, a gifted legislator, and a true gentleman who deeply loves his state and his country,” said Sen. Deb Fischer (R-NE).

“We will surely miss him,” said Sen. John Cornyn (R-TX), who called Isakson a 'Wonderful human being and a great Senator.'

“Not only is Johnny a diligent and successful legislator, he is one of the kindest, most thoughtful senators,” said Senate Democratic Leader Charles Schumer.  “Independent of any party or politics, everyone will miss Johnny.”

“In his 40 years of service, Johnny has shown unwavering dedication to our state and our country,” said Rep. Tom Graves (R-GA).

“Johnny Isakson has been a standard of public service and statesmanship for decades in Georgia,” said Rep. Doug Collins (R-GA).

Isakson was one of a few GOP lawmakers who spoke up on behalf of the late Sen. John McCain (R-AZ) after repeated attacks by President Donald Trump.

“Anybody who in any way tarnishes the reputation of John McCain deserves a whipping,” Isakson said on the Senate floor, arguing that McCain's critics “didn’t have the guts to do the right thing when it was their turn” to serve in Vietnam.

“I would say to the President or anybody in the world, it is time to pause and say that this was a great man who gave everything for us. We owe him nothing less than the respect that he earned,” Isakson added.

That support for McCain was replicated for Isakson, as the Georgia Republican announced his resignation.

“Johnny Isakson is a giant among men,” said Rep. Austin Scott (R-GA)