Fans with game tickets will be offered free ground transportation between host cities at the 2018 World Cup in Russia.

Alexey Sorokin, the head of the Russian organizing committee, says "free travel is a guarantee that we signed at the highest level during our bid."

Speaking Saturday in Rio, Sorokin says train or bus travel will be offered between the 11 host cities, all located in the west of the country. Twelve stadiums will be used. Sorokin describes it as a "complicated" system that's being worked out.

Travel has been challenging — and expensive — at the last three major football tournaments, including this year's World Cup in Brazil, the 2012 European championship, and South Africa's 2010 World Cup.