South Korea is considering an entry ban on vessels that have traveled through North Korea as part of measures to punish Pyongyang for its nuclear and missile tests, sources here said Monday.

Seoul is tightening sanctions on Pyongyang as the communist country continues to develop nuclear weapons and missiles in defiance of international bans.

Last week, Seoul shut down a joint industrial complex in the North's border city of Gaeseong to cut what it said was the flow of money into Pyongyang's weapons of mass destruction program.

According to the sources, South Korea may ban the entry of foreign vessels that have called at North Korean ports and adopt other sanctions measures similar to those announced by Japan last week.

Japan has banned the entry of all North Korean ships and foreign vessels en route from North Korea and prohibited entry by crew members aboard North Korean ships or convicted of violating existing sanctions on the North.

All North Korean vessels have been banned from calling at South Korean ports or passing through South Korean waters under sanctions imposed after the North's deadly sinking of a South Korean warship in March 2010.

The new sanctions will likely be announced after the U.N. Security Council adopts a new sanctions resolution on Pyongyang in response to its fourth nuclear test on Jan. 6 and long-range rocket launch on Feb. 7, the sources said. (Yonhap)