London: FIFA general secretary Fatma Samba Diouf Samoura has warned England and Scotland they could face sanctions if their teams wear commemorative poppies in their November 11 game.
The football associations of England and Scotland have vowed to defy world governing body FIFA, which bans players from wearing political, commercial and religious symbols during matches.
People in Britain wear poppies to remember the country's war dead and England's FA said it would be an "appropriate tribute" for the players to wear black armbands with red poppy emblems.
But Samoura told the BBC: "We have to apply uniformly and across the 211 member associations the laws of the game.
"Britain is not the only country that has been suffering from the result of war. The only question is why are we doing exceptions for just one country and not the rest of the world?"
England play Scotland in a World Cup qualifier at Wembley on November 11, which was the date the Armistice was signed to end World War I in 1918.
Asked if the teams could be punished for defying the ban, Samoura said: "It is not really my ambition to punish anybody.
"They just have to recognise themselves that they are part of the rules of the game and they should be ready to face any kind of sanctions or measures."
FIFA could elect to dock points if England and Scotland do not respect the ban, but English FA chief executive Martin Glenn does not believe it will come to that.
"We don't think we are breaking their law -- we think they are misinterpreting it," he said. "I'm confident it won't come to anything draconian.
"We are standing shoulder-to-shoulder with the other home nations on this. We all feel very strongly. It's not a political symbol and I think most people would agree with us."
- Ireland case -
Glenn and his Scottish counterpart Stewart Regan were due to meet FIFA officials during a scheduled meeting of the International FA Board, football's rule-making body, at Wembley on Thursday.
British Prime Minister Theresa May has described FIFA's stance on the matter as "utterly outrageous" and a petition against the poppy ban has been signed by close to 300,000 people.
Arsenal manager Arsene Wenger has spoken out in support of the English and Scottish associations.
"I believe that, by wanting to be too politically correct, sometimes you go against tradition," the Frenchman told his weekly press conference.
"In this case, that is the part of English culture that I love. They respect tradition and they respect people who have given their life for their country. I think that FIFA should not get involved in that."
The issue last arose in November 2011, when England's players were allowed to wear armbands with poppies -- rather than poppy emblems -- on their shirts -- as a compromise.
The Football Association of Wales has also written to FIFA to ask for permission for Wales's players to wear poppies during their World Cup qualifier against Serbia in Cardiff on November 12.
It has emerged the Republic of Ireland's players wore jerseys commemorating the Easter Rising, a 1916 rebellion against British rule, during a friendly against Switzerland in March.
FIFA has subsequently been accused of double standards.
"That appears to be an absolutely classic example of leniency being shown to other countries," said British MP Damian Collins.
A spokesperson for FIFA said the governing body was considering sanctions against Ireland.
But FIFA sources said Ireland did not need to ask permission as it was a friendly game. There are different rules for World Cup matches and other official tournaments.