Japanese Ambassador to the United Nations Motohide Yoshikawa on Friday urged the U.N. Security Council to speed up efforts to adopt a new resolution to sanction North Korea for advancing its nuclear development program and said it should be the body's top priority.

"Japan believes that adopting a new resolution with further significant measures needs to be the top and urgent priority of this council," Yoshikawa said at a session wrapping up the month under Uruguay's rotating presidency.

While Yoshikawa pointed out that the 15-member council was "united" in releasing a news statement hours after Pyongyang's Jan. 6 nuclear test, negotiations on the contents of the new resolution are still being worked out mainly between China and the United States.