US President Donald Trump further broke ranks with Group of Seven allies, calling for Russian expulsion from the bloc to end. Picture: Reuters/Kevin Lamarque

Washington, United States - US President Donald Trump further broke ranks with Group of Seven allies Friday, calling for Russian expulsion from the bloc to end.

Departing the White House for a fractious summit with European, Canadian and Japanese leaders, Trump said their 2014 decision to suspend Russia from the group of the world's most advanced economies -- after Moscow annexed Ukraine's Crimea region -- should be reversed.

"I have been Russia's worst nightmare," Trump claimed, "but with that being said, Russia should be in this meeting.

"Why are we having a meeting without Russia being in the meeting?

"I would recommend -- it's up to them. But Russia should be in the meeting, should be a part of it."

Trump's comments are likely to cause consternation, especially among European allies furious at Russia's support of separatists in eastern Ukraine, assassination plots against Russian dissidents on European soil and meddling in Western elections, including Trump's election in the United States.

The US president has steadfastly refused to acknowledge that Russia had any substantive impact on his 2016 election, despite the verdict of his own spy agencies and a major FBI investigation that has looked into his campaign's ties with Russia.

Trump argued that Moscow was too important to isolate.

"They should let Russia come back in. Because we should have Russia at the negotiating table," he said.

Trump's comments are likely to be greeted warmly in Moscow, and perhaps too in Rome, where a new populist dominated government would like better ties with the Kremlin.