Former Russian President Dmitry Medvedev, who has sometimes raised the spectre of a nuclear conflict over Ukraine, said on Sunday that Moscow would have to use a nuclear weapon if Kyiv's ongoing counter-offensive was a success.

MOSCOW, July 30 (Reuters) - Former Russian President Dmitry Medvedev, who has sometimes raised the spectre of a nuclear conflict over Ukraine, said on Sunday that Moscow would have to use a nuclear weapon if Kyiv’s ongoing counter-offensive was a success.