New Komeito and the Democratic Party of Japan have separately submitted proposals for amending bills covering the updated Japan-U.S. defense cooperation guidelines to a board meeting of the Lower House special committee debating them, party officials said Friday.

The two opposition parties are proposing that the bills be revised to mandate that Self-Defense Forces missions in support of U.S. forces get prior Diet approval except in cases of "high-level emergencies."

What would constitute a high-level emergency was not clarified.