MOSCOW, May 30 (RIA Novosti) - Russian President Dmitry Medvedev and Japanese Prime Minister Taro Aso held a phone talk and urged a response to North Korea's nuclear test, the Kremlin said Saturday.
Since the start of the week Pyongyang has conducted an underground nuclear test explosion and test-launched at least six short-range surface-to-air and anti-ship missiles in defiance of previous UN resolutions.
"The sides were united that it is necessary to react seriously to these steps, which are a challenge to the system of international security," the Kremlin said.
Pyongyang is already under a number of UN sanctions over its first nuclear test, carried out in 2006.
