GENEVA - Japan's nuclear crisis may force volleyball's governing body to move two Olympic-qualifying World Cup events out of the country.

The International Volleyball Federation (FIVB) said Tuesday it could choose new hosts for the November tournaments for men and women when it meets next month.

"The key problem is the nuclear radiation," said FIVB President Wei Jizhong. "If not in Japan, we have to prepare two alternatives. They will need at least five months (to prepare)."

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The FIVB wants to reassure players about Japanese air quality after nuclear power plants were rocked by the devastating 9.0-magnitude earthquake and aftershocks.

Japan has hosted all the quadrennial World Cups since they became Olympic qualifiers in 1991.

The 2011 men's event is planned in several cities from November 4-18 and the women's edition would begin November 20. Each tournament is designed to allow three countries to qualify for their respective 12-team lineups at the 2012 London Olympics.

Wei, who met with Japanese officials last weekend at FIVB headquarters in Lausanne, said they wanted to continue as World Cup hosts. "We have to help Japan, because they are in a difficult situation, and respect their decision. We don't want to impose," the Chinese official said.

Wei said his organization awaited advice from nuclear experts and would "respect the willingness of the players" to compete in Japan.

The aftermath of the March 11 quake and tsunami has also affected the playing plans of Japan's national teams.

The FIVB said Tuesday that Japan's men have forfeited their right to home matches in the 16-nation World League beginning next month.

Japan will play only on the road after being scheduled to host two matches in June against each group rival - Germany (in Koshigaya), Russia (in Nagasaki) and Bulgaria (in Wakayama).

The Japanese women's team is also looking for different home venues to play World Grand Prix matches in August.

Volleyball is the latest sport seeing its international schedule affected by the natural disasters in Japan. The figure skating world championships were scheduled for last month in Tokyo but will now be held starting April 24 in Moscow.

The gymnastics worlds set to be held in Tokyo in October is another important London 2012 qualifier which could be switched. The International Gymnastics Federation has said it hopes to stay in Japan "without taking any risk for the health of the participants." Its executive committee will consider options at a meeting next month in San Jose, California.

An aerobic gymnastics World Cup event in Tokyo also was postponed until June and moved west to Hamamatsu. Japanese football clubs have postponed home fixtures in the Asian Champions League.