Republican presidential candidate Mike Huckabee on Monday promised to block a Supreme Court ruling striking down state bans on gay marriage if elected president.

The nation's highest court is expected at any moment to hand down a decision in a case challenging bans in Ohio, Michigan, Kentucky and Tennessee, which could lead to nationwide marriage equality.

During a radio appearance from Iowa, Huckabee said that as president he would ignore the court's ruling and veto any legislation legalizing marriage equality.

“Until the Congress of the United States puts on my desk a bill that basically defies the laws of Nature and Nature’s God and defies the longstanding tradition of marriage, the federal government will not recognize same-sex marriage because there is no law that requires it and that would be true for the military and it would be true for all federal institutions,” Huckabee said. “If the Congress decides that they want to pass enabling legislation, they could put it on my desk and I would veto it, and they can attempt to override it. That’s the process.”

Liberals will “rue the day when the sword they use to enact their agenda is the sword of the court rather than to do it by way of the people's elected representatives,” he said.

“There can be no surrender on the point of the Supreme Court decision on same-sex marriage,” he added, because such a ruling would go “to the heart of who we are as Americans and whether or not religious liberty lives or dies.”