Japanese Prime Minister Shinzo Abe told Asia-Pacific leaders on Sunday that North Korea's nuclear weapons and missile programs "cannot be tolerated", a Japanese official said.
"North Korea's launch of missiles and nuclear weapons test are grave threats to the peace and stability of not only our country but East Asia and international society," the official quoted Abe as telling leaders at the Asia-Pacific Economic Cooperation (APEC) summit.
"That is a big challenge to the non-proliferation of weapons of mass destruction. It cannot be tolerated."
Japan is one of five countries involved in negotiations with North Korea on dismantling its nuclear programme, which was put on display last month when it carried out its first nuclear test.
The talks stalled a year ago when Pyongyang walked out over US financial sanctions, but agreed late last month to return to the negotiating table, provided the financial curbs were on the agenda.
"We welcome the resumption of six-way talks, but holding the meeting itself is not a goal. It is necessary to continue pressuring North Korea to take concrete action for non-nuclearisation," the official quoted Abe as saying.
"It is necessary for all the members here to form a united front and work on North Korea," the Japanese prime minister, who took office in late September, told APEC leaders.