Japan's main opposition party has submitted to parliament a bill banning North Korean ships from entering the country's ports.

Under the bill, ships from North Korea cannot enter Japan's ports if they are deemed to pose a threat to the country's peace and security.

Sources say that depending on political situations in Northeast Asia, there is a possibilityof the bill being voted down at the Diet.

However, Japan's Asahi Shimbun said a deliberation on the bill would not take place for the time being as another bill. Pro-government parties also plan to submit a similar bill next week.

Concerning North Korea's abduction of thirteen Japanese nationals in the 1970s and 1980s, Japanese lawmakers said the country must exert stronger pressure on Pyongyang as the country has shown no signs of addressing the issue to bring about a swift resolution.