French President Emmanuel Macron

France President Emmanuel Macron slapped in the face

In a video circulating on social media, Mr Macron is seen walking up to a barrier on a trip to Tain-l'Hermitage outside the city of Valence.

A man in a green T-shirt slaps Mr Macron in the face before officers quickly move in. The president, meanwhile, is pulled away.

Two men have been arrested following the incident, French media report.

President Macron later called it an "isolated event".

"We must not let ultra-violent people take over the public debate: they do not deserve it," he told French newspaper Le Dauphiné.

Macron on track for French parliament landslide

As polls closed, projections showed La Republique en Marche (Republic on the Move) set to win more than 400 seats in the 577-seat National Assembly.

Mr Macron's party was established just over a year ago and many candidates have little or no political experience.

The second round of the vote is held next Sunday.

Forecasts by two polling organisations gave LREM well over 30 percent of first round votes.

But turnout was low, about 49 percent, which analysts said reflected a sense of resignation among Mr Macron's opponents.

Macron explains Trump handshake

"My handshake with him, it's not innocent," Macron told the Journal du Dimanche in an interview published Sunday. "It's not the alpha and the omega of politics, but a moment of truth."

The two newly-minted leaders met in Brussels on Thursday and shook hands in full view of the press.

Pool reporter Phillip Rucker of the Washington Post, who was in the room, described it: