The prospect of Russia rejoining the G7 group of the world’s leading industrialised nations will be used as part of a carrot and stick approach to persuade President Vladimir Putin to pull out of Syria, The Daily Telegraph understands.

Rex Tillerson, the US Secretary of State, will fly to Moscow later this week with an ultimatum from the G7 demanding that Putin withdraws his armed forces and ends his support for President Bashar al-Assad. Threats of new sanctions against Russia could be made if he does not comply.

But alongside the hardline approach being taken by America and its Western allies, diplomats will be working behind the scenes to offer Mr Putin a way to regain his place at the G7, something he is said to covet.