Republican presidential frontrunner Donald Trump is not about to soften up in his proposals on how to combat terrorism in the United States.

In an interview on ABC's "This Week," the controversial business mogul said he is in favour of subjecting suspected terrorists to water torture to be able to draw out essential information from them.

Trump said subjecting terror suspects to waterboarding—a harsh interrogation process where a person is almost drowned with huge amounts of water while strapped on a downward-sloping board—seemed reasonable considering the great amount of harm they cause the public.

"I would bring it back, yes. I would bring it back. I think waterboarding is peanuts compared to what they'd do to us," Trump said, as quoted by NBC News.

"We have to be strong. You know, they don't use waterboarding over there; they use chopping off people's heads," he added.

The tough-talking business tycoon also maintained that the U.S. government must maintain a database of Syrian refugees entering its territory, as part of additional safeguards against terrorism.

"When the Syrian refugees are going to start pouring into this country, we don't know if they're ISIS, we don't know if it's a Trojan horse," Trump said.

The Republican presidential aspirant also once advocated for the surveillance of some mosques, to ascertain that these places of worship for Muslims are not being used for terrorist activities.

"There are certain hot spots, and everybody knows (the mosques) are hot spots," Trump told ABC's George Stephanopoulos.

The businessman-turned-politician also used the interview as an opportunity to highlight his lead in recent Republican presidential preference polls.

"I'm leading every poll by a lot. It's not even a little bit anymore, it's a lot," Trump said.

Asked further if he is open to running an independent campaign amid rumours that some of his fellow Republicans are working against him, Trump replied, "I'm going to have to see what happens ... If I'm treated fairly, I'm fine. All I want to do is a level playing field."

Last Friday, an NBC News/SurveyMonkey poll showed Trump reclaiming his frontrunner status from his closest rival, retired neurosurgeon Ben Carson. Trump secured the support of 28 percent of the respondents in the latest survey.