Russia and Ukraine will be put into different groups at the 2018 World Cup finals if the Ukrainians qualify and relations between the two countries do not improve, FIFA president Sepp Blatter said.

"You can be sure about this," said the head of world soccer when asked by R-Sport agency whether the two teams would be kept apart given the current poor political climate with Kiev accusing Moscow of backing Russian separatists in the east of Ukraine.

Blatter, who was on a visit to Moscow for the unveiling of Russia's official World Cup emblem, said political situations around the world should not have an impact on sport. There have been calls to move the 2018 tournament to a different country due to Russia's conflict with Ukraine.

"A boycott never achieves anything and does not have a positive effect. FIFA is fully supporting the World Cup in Russia," said the 78-year-old.

"When we received letters from North America, we answered that this is football. We believe in the country (Russia) and their government.

"The mass media should help us with this. We have experienced such things in the past at the Sochi Olympics. However, during and after the (Winter) Games there was not one bad word written about the event.

"Russia is the world's biggest country. You know, Russia is in the focus of the world press. Football cannot only unite Russia, but can also show the whole world that it is stronger than any protest movement," he said.