The leaders of the Group of Seven (G7) rich nations must condemn any threat to use nuclear weapons and vow "decisive action" against such a move when they hold a summit next week in the city of Hiroshima, Ukraine's envoy to Japan said.
Nuclear tension has surged since the start of the conflict with Ukraine as President Vladimir Putin has repeatedly warned that Russia is ready to use its nuclear arsenal, if necessary, to defend its "territorial integrity."
