Former president George H.W. Bush on Thursday formally endorsed Mitt Romney’s presidential bid, quoting country music legend and Houston native Kenny Rogers in urging the Republican Party to “know when to hold ‘em” and “when to fold ‘em.”

Former Massachusetts governor Mitt Romney meets with former president George H.W. Bush in Houston last December. (AP Photo/Pat Sullivan)

Bush, who had signaled his support for Romney late last year in an interview with the Houston Chronicle, made the endorsement official Thursday afternoon in Houston with his wife, former first lady Barbara Bush, and Romney, the GOP frontrunner.

“Barbara and I are very proud to fully and enthusiastically endorse and support our old friend, Mitt Romney,” the 41st president said, according to a pool report of the event. “He’s a good man, he’ll make a great president, and we just wish him well.”

He then asked his wife whether she wanted to add any remarks.

“Aren’t you going to sing a song for us?” Barbara Bush asked her husband. “’Know When to Fold ‘Em?’”

“Yeah, I do think it’s time for the party to get behind Governor Romney,” Bush replied. “And she was reminding me Kenny Rogers sang, ‘It’s time when to hold ‘em and time when to fold ‘em.’ Well, I think it’s time for people to all get behind this good man.”

Some of Romney’s opponents, he added, “waged a very good fight.”

“We’re so convinced and we’ve known Mitt for a very long time, that he’s the man to do this job and get on and win the presidency, and that’s about it,” Bush said.

Romney has enjoyed a long personal friendship with Bush and was endorsed last week by Bush’s son, former Florida governor Jeb Bush (R). Barbara Bush also recorded robocalls for Romney earlier this month in Vermont and Ohio.

In a statement, Romney cited Bush’s career as “a naval aviator, congressman, ambassador, CIA director, vice president, and president” and said that he had “served our country with great devotion and high distinction over many decades.”

“When we talk about the Greatest Generation, we are talking about those like President Bush, who, after Pearl Harbor, enlisted in our armed forces and served with unflinching courage during World War II,” Romney said. “This is a man who knows from the ground up — and from the top down — the meaning of responsibility in exercising leadership in our democracy. I am proud to have him as my mentor.”

The endorsement comes near then end of a week that has seen GOP support further consolidate around Romney’s presidential bid.

Late Wednesday, Sen. Marco Rubio (R-Fla.) threw his support behind Romney, telling Fox News Channel’s Sean Hannity that “it’s increasingly clear” that the former Massachusetts governor will be the GOP nominee.

Romney also this week won the support of House Majority Whip Kevin McCarthy (Calif.), the chamber’s No. 3 Republican, and Sen. Mike Lee (R-Utah), like Rubio a tea-party favorite who was elected in 2010.