G7

In a statement, Sir Keir said he and other G7 partners were finalising the new measures at the Alberta summit, and that they would "squeeze Russia's energy revenues and reduce the funds they are able to pour into their illegal war".

Asked why limited information had been released about the contents of the sanctions package, a No 10 spokesman said: "It's just a point of fact that the G7 has only just begun... it would be premature to get ahead of what those sessions will yield."

There were signs of division earlier at the G7 over conflicts between Russia and Ukraine and between Israel and Iran.

The leaders of G7 nations have called for a "de-escalation of hostilities in the Middle East, including a ceasefire in Gaza".

"Iran is not winning this war, and they should talk... before it's too late," he told reporters at the G7 summit in Canada.