Sen. Bob Corker (R-Tenn.) said Friday that he will support the GOP tax plan, all but guaranteeing that Republicans will have the votes needed to pass their tax bill next week.

Corker said that the final legislation represents a "once-in-a-generation opportunity." His decision is a reversal from the Senate tax plan passed earlier this month, which he opposed over concerns that the bill would not pay for itself and would add to the deficit.

"I know every bill we consider is imperfect and the question becomes is our country better off with or without this piece of legislation. I think we are better off with it. I realize this is a bet on our country's enterprising spirit, and that is a bet I am willing to make," Corker said in a statement Friday.

He added that "after many conversations over the past several days with individuals from both sides of the aisle across Tennessee and around the country ... I have decided to support the tax-reform package we will vote on next week."

GOP leadership and administration officials have been working with Corker to try to get him to support the final tax legislation despite his previous insistence that he would not vote for a plan that adds "one penny's worth of deficits."

The White House said President Trump expressed personal appreciation for Corker's support, indicating that the GOP senator had reached out by phone about his decision.

"The President greatly appreciates Senator Corker's phone call and pledge to support tax cuts. He sees a great entrepreneurial spirit being released in our country and he is a part of that spirit. When these massive tax cuts and incentives kick in, jobs and growth will follow at a very high level," White House press secretary Sarah Huckabee Sanders said in a statement.

With Corker's support, Senate Republicans likely have the votes needed to pass their tax bill next week even as they face potential absences from some members, including Sen. John McCain (R-Ariz.), who is being treated at Walter Reed Medical Center.

Sen. John Cornyn (R-Texas) hinted earlier Friday that Corker could be a "yes" on the tax deal, saying there could be a "surprise" on who supports the legislation.

"I was thinking specifically about Sen. Corker who did not vote for the Senate bill, who we are working with and I think is encouraged by the direction that this House-Senate conference is going in," Cornyn told KSKY, a Texas radio station.

Corker's announcement Friday came shortly after fellow GOP Sen. Marco Rubio (Fla.) came out in support of the tax legislation. Rubio had told reporters he was a "no" on Thursday as he angled to get changes made to the child tax credit.

Corker acknowledged Friday that the tax deal, a compromise proposal that merges the House and Senate bills, "is far from perfect."

"Left to my own accord, we would have reached bipartisan consensus on legislation that avoided any chance of adding to the deficit and far less would have been done on the individual side with items that do not generate economic growth," he said.

Republicans have a 52-seat majority, meaning they can only afford to lose two GOP senators, if every Democrat and independent votes "no," and still permit Vice President Pence break a tie.

McCain and Sen. Thad Cochran (R-Miss.) missed Senate votes this week. But Cochran's office noted that he will be back next week to vote for the tax plan.

GOP Sens. Mike Lee (Utah), Susan Collins (Maine) and Jeff Flake (Ariz.) have yet to say if they will support the final agreement, but they each voted for the Senate legislation.

- Jordan Fabian contributed

Updated: 4:08 p.m.