The US is hoping their fresh sanctions on Russia - which are set to be announced at the summit - will convince the other G7 countries to increase theirs.

Washington says the new measures - which include banning 70 entities from receiving US exports as well as another 300 new sanctions on other individuals or entities - are aimed at crippling Moscow’s "war machine" in Ukraine.

The war in Ukraine, now in its 15th month, is at the top of the summit agenda and countries which haven't been openly critical of Russia - such as additional guest India - may be under pressure to act. India has declined to adhere to Western sanctions on Russian imports.

So far, the EU and the UK have flagged they will crack down on Russian diamonds. A US government spokesperson told media this morning they expect all G7 members will unveil new measures over the weekend.