A forthcoming U.S. congressional bill seeks to keep North Korea on the American list of terrorism-sponsoring countries until Pyongyang releases all Japanese nationals it kidnapped.

Japan's Kyodo News Agency says the bill will be submitted to Congress as early as Monday.

Initiated by Republicans, the bill also says North Korea should stay on the terrorism list unless it verifiably scraps its nuclear program and promises not to export nuclear materials and missile technology to Iran and Syria.

Kyodo says it is uncertain if the bill will be put to a vote at a plenary session after passing the House committee on foreign affairs.