PARIS (Reuters) - France must "annihilate" Islamist radicals and regain control of its borders, the far-right National Front party leader Marine Le Pen said on Saturday after deadly attacks in the French capital.

"Urgent action is needed," Le Pen told reporters the day after 127 people were killed in assaults on cafes, a concert hall and a soccer stadium.

"Islamist fundamentalism must be annihilated, France must ban Islamist organizations, close radical mosques and expel foreigners who preach hatred in our country as well as illegal migrants who have nothing to do here," she said.

Islamic State claimed responsibility on Saturday for a coordinated assault by gunmen and bombers at locations across Paris, which President Francois Hollande said amounted to an act of war against France.

Polls have been suggesting that Le Pen, known for her strong speeches against immigration, is likely to win regional elections in northern France in December. Surveys also see her making it to the second round of the presidential election in 2017, although not winning the run-off.

Europe is facing a chaotic flow of migrants, many of them from predominantly Muslim countries, seeking peace and prosperity in Europe. Close to a million people have entered the bloc over the past few months, threatening Europe's unity as its leaders argue about how to handle the crisis.

"It is absolutely necessary that France regains control of its borders," she said.

(Reporting by Sybille de La Hamaide; Editing by Andrew Callus)