The FBI has confirmed that its investigation of alleged corruption at FIFA will include scrutiny of Russia and Qatar's successful World Cup bids.
An anonymous law enforcement official told Reuters that the reviews are part of a probe that goes beyond the accusations of bribery in a US indictment of FIFA officials.
Both Russia and Qatar have denied any wrongdoing in the way they conducted their bids, and have vowed to resist any attempts to strip their countries of the tournament.
"It is very difficult for some to digest that an Arab Islamic country has this tournament, as if this right can't be for an Arab state," said Qatar foreign minister Khaled al-Attiyah.
"I believe it is because of prejudice and racism that we have this bashing campaign against Qatar."
Russia have pledged to co-operate with the FIFA investigations, but a spokesperson for president Vladimir Putin has insisted that preparations for the 2018 World Cup are ongoing.
FIFA president Sepp Blatter announced his decision to step down earlier this week, six days after police raided a hotel in Zurich and arrested several officials from the governing body.
Switzerland plans to launch its own investigation into the decision to award World Cups to Russia and Qatar.
