Japanese Prime Minister Fumio Kishida warns that Russia using nuclear weapons would be seen as an "act of hostility against humanity".
Speaking in Australia, Kishida said the 77-year period of no nuclear weapons use "must not be ended".
Ukraine war: Russia nuclear weapon threats are 'most serious' since Cuban Missile Crisis, says Biden
"For the first time since the Cuban Missile Crisis, we have a direct threat to the use of nuclear weapons," the US president said.
euronews (in English)