Russia's Medvedev: We'd have to use a nuclear weapon if Ukrainian offensive was a success

Putin said on Saturday that there were no serious battlefield changes to report in recent days and that Ukraine had lost large amounts of military equipment since June 4.

Russian Security Council Deputy Chairman and the head of the United Russia party Dmitry Medvedev, second left, talks with officers as he visits the Totsky military training ground in the Orenburg region, Russia. Picture: Ekaterina Shtukina, Sputnik, Pool Photo via AP

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.

Medvedev, who is deputy chairman of Russia's Security Council, a body chaired by President Vladimir Putin, said in a message on his official social media accounts that Russia would be forced to fall back on its own nuclear doctrine in such a scenario.