The ex-president’s warning comes after Poland said Washington would hit Russian targets if Moscow were to use nukes in Ukraine Deputy head of Russia’s Security Council and chairman of the United Russia political party Dmitry Medvedev. © Sputnik/Ekaterina Shtukina

Any US attack on Russian targets in Ukraine would automatically trigger a world war, former Russian President Dmitry Medvedev has warned.

The official, who currently serves as Deputy Chair of Russia’s Security Council, made the remarks after Polish Foreign Minister Radoslaw Sikorski claimed Washington had threatened to conduct such a strike should Russia use nuclear weapons in Ukraine.