Japan's Upper House of Diet on Friday officially approved a ban on port calls by North Korean boats that was imposed after the communist regime conducted a nuclear test in October.
Japan has been stepping up pressure on North Korea over the Oct. 9 test, barring its ships from Japanese ports, and banning North Korean goods and citizens from entering the country since Oct. 13.
Friday's approval of the ship ban is retroactive. It will be in force for six months from October.
The more powerful Lower House approved the measure earlier this month.
Japan already had limited sanctions against North Korea, imposed after the North test-fired seven missiles into waters between Japan and the Korean peninsula in July.
Those sanctions included banning the Mangyongbong-92, a North Korean ferry that served as a major trade conduit between the two countries, from entering Japanese waters. Japan and North Korea have no formal diplomatic ties.
The trade ban is believed to serve a blow to North Korea, which earned foreign currency by shipping marine and agricultural produce to Japan.
Negotiations on ending North Korea's nuclear weapons program are set to resume Monday in Beijing, a year after the North walked out. The talks involve Japan, China, Russia, the two Koreas and the United States. (AP)