London: Prime Minister Theresa May said on Friday Britain stood shoulder to shoulder with France after the Nice attack that killed over 80 people and was reviewing whether the UK needed to do more to boost its own security.

"I will speak to President (Francois) Hollande today and make clear that the United Kingdom stands shoulder to shoulder with France today as we have done so often in the past," she said.

"The threat level here in the United Kingdom is already at severe, that means that a terrorist attack is highly likely," she added in broadcast remarks. "Senior officials today will be reviewing what more we can do to ascertain whether there is any further action we need to take."

May, who took over as prime minister on Wednesday with the job of steering Britain out of the European Union, said her deputy national security adviser would chair the review.