Japan appears ready to impose additional sanctions on North Korea in the wake of Pyongyang's July test firing of several missiles.
Japanese officials indicate new sanctions could be imposed on North Korea as early as next Tuesday.
Chief Cabinet Secretary Shinzo Abe, who is expected to take over as prime minister next week when Junichiro Koizumi steps down from the post, confirmed the government is considering additional measures.
Calling North Korea's recent missile launches a challenge to the international community, Abe says Japan wants to increase the pressure on Pyongyang in accordance with the subsequent U.N. Security Council resolution.
That resolution condemned the missile tests, and called for sanctions against North Korea in retaliation.
Cash-strapped North Korea has traditionally been dependent on financial support from ethnic Koreans in Japan who support Pyongyang.
Japanese media reports say the government is expected to stop these North Korea-bound remittances, and freeze the financial assets of groups and individuals in Japan that are believed to have aided Pyongyang's weapons programs.
Japan has already imposed a ban on North Korean officials visiting here, and stopped the only direct passenger link - a North Korean ferry - between the two countries. The two countries have no official diplomatic relations.
Foreign Ministry spokesman Tomohiko Taniguchi says no official date has been decided for announcing new sanctions.
"We're certainly discussing what [is] to be done as a next step to heighten the pressure against North Korea, perhaps involving the financial sanctions," he said.
North Korea shot off a barrage of missiles into the Sea of Japan in July. U.S., South Korean and Japanese media have also reported that Pyongyang may be preparing additional missile tests and an underground nuclear weapons detonation.
Japanese officials say that another reason for imposing further sanctions is that North Korea shows no signs of returning to six-party talks about its nuclear weapons programs. North Korea has said it will not return to the talks until the United States removes sanctions Washington imposed separately last year, aimed at curbing alleged counterfeiting and money-laundering by Pyongyang.
No session of the talks - which involve the two Koreas, the United States, Japan, Russia and China - has been held since last September.