U.S. President Barack Obama has been sent a letter signed by 22 senators urging him to address the issue of international parental child abductions during his summit in Tokyo this week with Prime Minister Yukio Hatoyama.

"This is a deeply important issue, as Japan currently does not recognize international parental child abduction as a crime," the senators, including former presidential candidate John Kerry, said in the letter dated Thursday. "We urge you to ensure that the United States continues to raise this issue at the highest possible levels in the context of our close bilateral relationship with Japan."

Foreign fathers who divorce Japanese wives typically cannot see their children because Japanese law allows only one divorced parent to have custody and Japanese courts usually rule in favor of Japanese mothers, even if they forcefully take their children away from their former husbands.