Rick Santorum backs Mitt Romney

Failed US Republican presidential candidate Rick Santorum has formally endorsed his former rival Mitt Romney.

In a late-night email, he urged his supporters to back the presumptive nominee in order to deny President Barack Obama a second term.

Santorum said he was impressed by Romney’s “deep understanding” of economic and family issues, following a meeting with him last week.

His support may now help Romney win over religious conservatives.

Rick Santorum ended his bid for the White House in April after Romney achieved an unbeatable lead.

“Above all else, we both agree that President Obama must be defeated. The task will not be easy. It will require all hands on deck if our nominee is to be victorious,” he said.

“Governor Romney will be that nominee and he has my endorsement and support to win this the most critical election of our lifetime,” he added.

Santorum clashed bitterly with Romney during the caucuses. At one point, he called Romney the worst Republican in the country to challenge Obama.

But following “candid” discussions in Pittsburgh on Friday, which focused on the family and its “foundational role in America’s economic success”, Santorum, said they had found common ground.

He said they agreed “the need for lower taxes, smaller government, and a reduction in out-of-control spending”.

“We certainly agree that abortion is wrong and marriage should be between one man and one woman,” he added, according to BBC.