U.S. President Donald Trump's tie flies up in the wind as he arrives to attend the nearby G7 Summit in Charlevoix after landing aboard Air Force One at Canadian Forces Base Bagotville in La Baie, Quebec, Canada, June 8, 2018.
UK Prime Minister Theresa May has said she wants the European Union to act with restraint and proportion in retaliating to the USA tariffs.
This year's G7 summit comes at a time, when leaders of seven major economies view the current global order as a historic division between Washington and its major allies in North America, Europe and Asia.
"Look, all of these countries have been taking advantage of the United States on trade", Trump told reporters as he left the White House, repeating his longstanding complaints about trade deficits and tariffs.
Iranian President Hassan Rouhani, whose country is an observer member of the SCO, will also attend the summit at a time when China and Russian Federation are seeking to save the Iran nuclear deal following the U.S.' withdrawal from the pact.
Conte, who is attending his first summit, had earlier indicated that he was in favour of Trump's proposal to welcome Russian Federation back into the organisation, which it was ejected from after annexing Crimea in 2014.
"Looking forward to straightening out unfair Trade Deals with the G7 countries", Trump tweeted early on Friday.
The two have met 25 times - five times previous year alone, according to Putin's foreign affairs adviser, Yuri Ushakov.
But Mr Trump predicted the G7 countries would agree on a joint statement after holding talks with Canadian Prime Minister Justin Trudeau.
Trump's Russian Federation comment won a quick endorsement from Italian Prime Minister Giuseppe Conte, who said on Twitter that Russia's re-admission would be "in everybody's interest".
Trump's administration last week announced an end to exemptions from steel and aluminum tariffs that had been granted the Canada, Mexico and the EU.
At least three of Trump's fellow Republicans in the U.S. Senate, all frequent critics of the president, assailed his suggestion of readmitting Russian Federation to the group. Tension between President Donald Trump and traditionally close USA allies has overshadowed that global meeting.
Conte's decision to side with the United States may irritate his European allies, who have so far declined to make any overtures to Russian Federation - though previous Italian governments have expressed hopes that Russian Federation would one day return, as has Japan. On Thursday, Macron threw down a gauntlet to Trump, saying that the rest of the G7 had no problem negotiating without him.
"Whether you like it or not - and it may not me politically correct - but we have a world to run..."
"There is no doubt that foreign interference in our democratic institutions and processes, and other forms of hostile activity, pose a strategic threat to our shared values and interests", British Prime Minister Theresa May said at the G7 Summit on Saturday.