Senate Republican Leader Mitch McConnellAddison (Mitch) Mitchell McConnellLawmakers feel pressure on guns Bipartisan group of House lawmakers urge action on Export-Import Bank nominees Curbelo Dem rival lashes out over immigration failure MORE (Ky.) said Tuesday he supports Mitt Romney's bid to win the Republican presidential nomination.

"I support Mitt Romney for president of the United States," McConnell said.

He predicted Romney would be the nominee and said the GOP is unifying behind his campaign.

McConnell's announcement came hours after House Speaker John BoehnerJohn Andrew BoehnerRestoring fiscal sanity requires bipartisan courage GOP congressman slams primary rival for Ryan donations Speculation swirls about Kevin McCarthy’s future MORE (R-Ohio) said he would back Romney. The former Massachusetts governor has been lining up party leaders and establishment Republicans behind his bid, particularly after rival Rick Santorum exited the presidential campaign.

"We're all looking forward to the fall campaign, which is already under way," McConnell said.

McConnell cited a recent tracking poll showing Romney ahead of President Obama by a few points in a hypothetical match-up.

The GOP leader urged his party to unify behind Romney during a television appearance earlier this month.

Romney still faces Newt Gingrich and Ron Paul in the primary process, but the two of them are unlikely to catch up to him the delegate count, leaving Romney the likely nominee.