Donald Trump has said the Paris terrorist attack would boost Marine Le Pen's presidential chances after a last-minute poll gave her a modest increase in support.

The US president said the shooting would "probably help" Ms Le Pen in Sunday's election, because she is "strongest on borders, and she's the strongest on what's been going on in France."

"Whoever is the toughest on radical Islamic terrorism, and whoever is the toughest at the borders, will do well in the election," he said.