While Japan awaits confirmation on whether North Korea actually carried out a nuclear test, government ministers in Tokyo are considering what additional sanctions to impose on the communist state.
Japan on Tuesday said it is trying to get the United Nations Security Council to quickly impose punitive measures against North Korea.
Foreign Ministry spokesman Tomohiko Taniguchi says that takes priority over any unilateral steps Japan will take against North Korea, which claims to have exploded a nuclear device.
"Some [sanctions] may take new legislation and some may not. But the Japanese government is, at the moment, very much single-mindedly focused on what's to be done on the U.N. Security Council floor," he said.
The United States, Japan, Britain and France are pushing for sanctions against North Korea under Chapter Seven of the world body's charter. That section mandates a council response to threats to international peace or acts of aggression.
Prime Minister Shinzo Abe told parliament on Tuesday that his government is likely to impose wide-ranging sanctions.
Mr. Abe says Japan will take swift and stern measures independent of the United Nations but the content of such sanctions is still being discussed.
Although Japan has no diplomatic relations with North Korea, there is some $200 million worth of legitimate two-way trade a year.
The communist state exports expensive mushrooms, clams and other agricultural and marine products to Japan. North Korea's rusty freighters usually depart Japan loaded with used appliances and second-hand vehicles and bicycles.
Japanese government sources have told VOA that a ban on all imports from North Korea is being discussed, as well as additional financial sanctions.
At present, about 200 smaller Japanese banks have relations with North Korean financial institution - transferring funds from ethnic Koreans in Japan to North Korea.
Japan's largest banks no longer permit such remittances to Pyongyang.
After North Korea test-fired missiles in July, Japan imposed limited financial sanctions on some organizations allegedly associated with Pyongyang's weapons programs. North Korean government officials also were banned from entering Japan.
Japan's lower house of parliament Tuesday unanimously adopted a non-binding resolution condemning North Korea's claimed nuclear test. The resolution demands that Pyongyang give up all of its nuclear weapons and related programs.