Referees can stop games over discriminatory or racist incidents at World Cup
Referees will have the power to stop or abandon World Cup matches in Russia if discriminatory incidents take place, says Fifa president Gianni Infantino.
It is part of a "three-step procedure" that gives officials the power to stop, suspend and call off fixtures over fan behaviour and was trialled at last summer's Confederations Cup.
Infantino said anti-discrimination measures were a "high priority" for football's world governing body.
"We will be very, very firm," he added.
"We can expect fair play in Russia. We'll make sure that no incidents will happen."
The trial at the Confederations Cup included deploying anti-discrimination observers - a continuation of the monitoring system put in place for 2018 World Cup qualifiers and selected friendlies.
The observers were co-ordinated and trained by the Football Against Racism in Europe (Fare) network, reporting incidents to Fifa's disciplinary committee for review and potential action, though no games were affected.
Fifa has previously called the level of racism in the Russian game "completely unacceptable" and players including Brazil and former Zenit St Petersburg forward Hulk have voiced concerns over racism at Russian games.
Last month Spartak Moscow were ordered to play a European home match in a partially closed stadium as punishment for racist behaviour by supporters during a Uefa Youth League game against Liverpool.
Officials in Russia have previously said they are working to kick out racism.