Updated at 8:55 a.m. ET
House Budget Committee Chairman Paul Ryan on Friday endorsed Mitt Romney for president, making him the latest high-profile Republican to get behind the frontrunner for the GOP nomination.
"I am convinced that Mitt Romney has the skills, the tenacity, principles, the courage and integrity to do what it takes to get America on track," Ryan said on Fox News. However, the congressman added there was more motivating his endorsement.
"I think this primary has been productive, I think it's been constructive, up 'til now," he said. But "I think we're entering a phase where it's counterproductive if it drags on much longer. We need to coalesce around Mitt Romney and focus on the task, which is defeating Barack Obama."
The Wisconsin lawmaker's endorsement comes just ahead of his state's primary on Tuesday. The latest poll out of Wisconsin, from NBC/ Marist, shows Romney with a solid, seven-point lead over his rivals. Romney takes 40 percent while Rick Santorum wins 33 percent support, Ron Paul wins 11 percent and Newt Gingrich takes 8 percent.
Romney has already accumulated 554 delegates, according to CBS News estimates, giving him a seemingly unsurpassable lead in the race to the 1,144 delegates needed to win the Republican presidential nomination outright. Santorum has only 241 delegates, Gingrich has 128 and Paul has 42.
In spite of that lead, Romney's GOP rivals don't appear ready to exit the race. As the contest drags on, a number of Republicans are saying publicly it's time for the party to get behind Romney.and also endorsed Romney this week.
When asked whether he's talked with Romney about serving as vice president should Romney win the nomination, Ryan said on Fox, "We've never discussed that at all" and insisted "my focus has been on the budget."
The Republican-led House on Thursday; the budget has no chance of becoming law but serves as a marker for the Republican agenda. It also makes Republicans vulnerable to attacks from Democrats who say Ryan's plan would dismantle Medicare and lead seniors " ."