Republican frontrunner Donald Trump on Monday unveiled his first TV ad of the presidential election campaign, demanding a ban on Muslims entering the United States and vowing to decapitate the Islamic State group.

The 30-second ad will be broadcast in Iowa and New Hampshire from Tuesday, costing $2 million a week ahead of the state's first-in-the-nation voting contests, his campaign said.

"The politicians can pretend it's something else but Donald Trump calls it radical Islamic terrorism -- that's why he's calling for a temporary shutdown of Muslims entering the United States," says the voiceover on the ad.

The commercial opens with footage of the billionaire candidate addressing a rally before segueing into an image of President Barack Obama and Democratic frontrunner Hillary Clinton, and then mug shots of the couple responsible for the San Bernardino killings last month.

"He'll quickly cut off the head of ISIS and take their oil," added the male speaker, referring to the IS extremist group based in Iraq and Syria that allegedly inspired the couple.

"And he'll stop illegal immigration by building a wall on our southern border that Mexico will pay for," the commercial added.

Iowa votes first in the nation in the nomination race, on February 1, followed by New Hampshire eight days later.

"I am very proud of this ad. I don't know if I need it, but I don't want to take any chances," Trump said Monday.

The real estate tycoon, who is funding his own campaign, has boasted of spending no money on political television ads until this one.

He has led the polls for months, using his bombastic and provocative style to dominate the media spotlight, without spending any of the $35 million he said he had expected to use on ads by January 1.

He claims to have spent the least money of all the candidates on the campaign trail and of still achieving "the best results," saying, "This is the kind of thinking the country needs."

Trump has previously run radio ads and will launch a new one this week featuring Kathryn Gates-Skipper, the first female Marine to serve in combat operations, his campaign said.

Later on Monday, he is scheduled to address a political rally in Lowell, Massachusetts, followed by another in Claremont, New Hampshire on Tuesday.

His call for a total, if temporary, ban on Muslims entering the country has been roundly condemned across the world and features in a video made by Al-Qaeda's affiliate in Somalia to encourage Western Muslims to wage jihad.