The Group of Seven ministers from Britain, Canada, France, Germany, Italy, Japan and the United States, along with the EU, meet in the remote tourist town of La Malbaie for two days of meetings that in the past have broadly been consensual on the issues they face.
Top of the agenda for Washington's partners will be US Secretary of State Marco Rubio's talks on Tuesday with Kyiv in Jeddah, Saudi Arabia, where Ukraine said it was ready to support a 30-day ceasefire deal.
But in the run-up to the first G7 meeting of Canada's presidency, the crafting of an agreed all-encompassing final statement has been tough.
A US decision to impose 25 per cent tariffs on all steel and aluminium imports immediately drew reciprocal measures from Canada and the EU, underscoring the tensions.
Washington has sought to impose red lines on language around Ukraine and opposed a separate declaration on curbing Russia's so-called shadow fleet, a murky shipping network that eludes sanctions, while demanding more robust language on China.
On Monday, Rubio cautioned that Washington did not want language that could harm efforts to bring Russia and Ukraine to the table.
Speaking to reporters on Wednesday, he said a good G7 statement would recognise the United States had moved the process to end the war forward.
The United States, since Trump's return to office on January 20, has taken a less-friendly stance on Ukraine, pushing for a quick deal to end the war, demanded European partners take on more of the burden without openly endorsing their role in future talks, and warmed Washington's ties with Moscow.
"It's very difficult. Maybe we should wait for the G8," said one European diplomat ironically.
Trump has suggested the G8 might be revived with the return of Moscow 11 years after its membership in the group was suspended over its annexation of Crimea.
Nowhere have the difficulties for US allies been more apparent than in Canada.
Relations between the United States and Canada are at a new low thanks to Trump's threats to impose tariffs on all imports from Canada and his constant musing about annexing the country to make it the 51st US state.
"We're going to be focused in the G7 on all of those things. That's what the meeting is about. It is not a meeting about how we're going to take over Canada," Rubio told reporters, highlighting how offbeat their ties have become.
That might not appease Ottawa. Foreign Minister Melanie Joly said on Wednesday she would be on the offensive at the G7.
"In every single meeting, I will raise the issue of tariffs to co-ordinate a response with the Europeans and to put pressure on the Americans," she said.
