Myrtle Beach: Republican presidential hopefuls have shown their willingness to challenge Iran after an incident in Gulf waters.

The US said that Iranians on Sunday threatened US Navy ships at the Strait of Hormuz. Iranian denied the claim, saying its officers were only trying to identify the vessels.

"I think an incident like this reminds us that we shouldn't be lulled into some false sense of confidence about Iran," former New York Mayor Rudy Giuliani said during the Fox News Channel debate on Thursday.

"I believe it was a very serious act," former Massachusetts Gov. Mitt Romney said. "And the Iranians continue to take acts like this, it points out that we have in Iran a very troubled nation."

The tough words about Iran by the Republican hopefuls came in South Carolina, where nominating contests will be held on January 19.

Former Arkansas Gov. Mike Huckabee, winner in last week's Iowa caucuses, said Iran and other countries should not expect limited response from the United States if attacked.

"Be prepared, first, to put your sights on the American vessel. And then be prepared that the next things you see will be the gates of Hell, because that is exactly what you will see after that," he said.

Representative. Ron Paul, dismissed the comments as unnecessary war rhetoric. "This incident should not be thrown out of proportion to the point where we're getting ready to attack Iran over this," he said.