Ice hockey is most popular in Canada, Eastern Europe, Northern Europe, and the United States. Ice hockey is the official national winter sport of Canada. In addition, ice hockey is the most popular winter sport in Belarus, Croatia, the Czech Republic, Finland, Latvia, Russia, Slovakia, Sweden, and Switzerland. North America's National Hockey League (NHL) is the highest level for men's ice hockey and the strongest professional ice hockey league in the world. The Kontinental Hockey League (KHL) is the highest league in Russia and much of Eastern Europe. The International Ice Hockey Federation (IIHF) is the formal governing body for international ice hockey, with the IIHF managing international tournaments and maintaining the IIHF World Ranking. Worldwide, there are ice hockey federations in 76 countries.