Japanese Prime Minister Fumio Kishida said on Tuesday Russia's possible use of nuclear weapons is highly unpredictable and the situation must be closely watched.
Kishida's comment to reporters came after he attended a virtual meeting of G7 leaders on Russia's invasion of Ukraine.
"The situation does not at all allow any prediction. It requires serious, close attention," said Kishida, who comes from Hiroshima.
"For the past 77 years, the world has continued to put a stop to using nuclear weapons. This history of not using nuclear weapons must continue further."
(Reporting by Kiyoshi Takenaka. Editing by Jane Merriman)