VAR has officially been given the green light for use at the World Cup

Video assistant referees will be used at this year's World Cup in Russia after Fifa formally approved use of the technology at the tournament.

VAR has been trialled in some domestic English cup games this season, and has been used in Germany and Italy.

"We need to live with the times," said Fifa president Gianni Infantino.

"We wanted to give the referees tools so that they can make better decisions, and in the World Cup some very important decisions are made."

He added: "It's not possible that in 2018 everyone in their living room knows a few seconds after the play whether a referee has made a mistake and the referee doesn't."

Ifab said "the philosophy of VARs is 'minimum interference - maximum benefit' which aims to reduce unfairness caused by 'clear and obvious errors' or 'serious missed incidents'".

It added the incidents that would refer to would be in relation to:

1. Goal/no goal

2. Penalty/no penalty

3. Direct red card (not second yellow card/caution)

4. Mistaken identity (when the referee cautions or sends off the wrong player)