President Donald Trump, who is attending the G7 summit in Canada, says Russia should be part of the group.
Russia was expelled in 2014 after the annexation of Crimea, but President Trump said he wanted the country readmitted.
Colleagues from the then G8 stopped Russia after taking control of Crimea, saying it would stay until Russia “changed course”.
The accumulation of the meeting led to major disagreements between President Trump and other countries over the imposition of trade tariffs.
There are likely to be disagreements with the US president over Iran and climate change.
The G7 summit, which brings together the United States, Britain, Canada, France, Italy, Japan and Germany, is being held in La Malbaie, Quebec.
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Leaders of nations, which account for more than 60% of global net worth, meet annually. The economy is at the top of the agenda, although meetings are now always branching out to cover important global issues.
President Trump has said he regrets that the meeting has shrunk in size, arguing with most other G7 members on another issue.
He said: “You know, whether you like it or – and it may not be politically correct – but we have a world to rule in the G7, which used to be the G8, Russia has been thrown out. They must let Russia return. “
President Trump has found support in the form of newly installed Italian Prime Minister Giuseppe Conte, who tweeted that it was “in everyone’s interest” for Russia to be readmitted.
However, Canada, France and the United Kingdom immediately signaled that they continued to oppose Russia’s re-entry. A Kremlin spokesman said he was interested in “other formats” besides the G7.
Russian President Vladimir Putin is currently in Beijing, where he was awarded a medal of friendship by his Chinese counterpart Xi Jinping.