She added: "Here we have a situation of six against one, meaning there is still no sign of whether the USA will remain in the Paris accord or not".
The Turnbull government will support the Paris agreement on climate change regardless of whether or not the United States president, Donald Trump, pulls out, the environment minister, Josh Frydenberg, has signalled.
On leaving Sicily, Trump said he would make his decision next week.
"Issues about domestic climate change policy in the United States is a matter for the Trump administration", Frydenberg said.
UN Secretary General Antonio Guterres, who is also in Sicily for the meeting, told the BBC earlier that the accord would survive regardless of Mr Trump's position.
G7 nations risk unprecedented deadlock on Saturday after US President Donald Trump ditched the charm for snarls, resisting calls for concerted action on hot-button issues such as climate change.
"There's always opportunities to do more on trade, always opportunities to improve on trade deals", Trudeau said.
British Prime Minister Theresa May told reporters that the G7 leaders agreed that climate was a priority, despite the fact that Trump is still mulling over his final decision.
The President faces both internal and external pressure to yield to the climate change crowd, beginning with his daughter Ivanka and economic advisor Gary Cohn.
Trump's top aides have refused to address reports Trump's son-in-law - White House adviser Jared Kushner - and a Russian diplomat may have discussed setting up a secret communications channel between the Trump transition team and the Kremlin.
To the White House, Trump's first trip overseas was an embodiment of the promises he made as a candidate to put America's interests first and break through the guardrails that have long defined USA foreign policy. He described a "very robust conversation. a lot of give and take" in discussions that included leaders from Japan, Britain, France, Germany, Canada and Italy.
Meanwhile, Democrats are urging Trump not to withdraw from the agreement.
The rules of the NAFTA countdown mean Trudeau and Trump can not talk about specific issues that would be subject to negotiations, even though they did talk about Canada-U.S. trade, including softwood lumber. "There are no indications whether the United States will stay in the Paris Agreement or not", Merkel said.
The Paris agreement is broader than any previous climate deal.
President Donald Trump arrives for a family photo at the G-7 Summit expanded session in Taormina, Sicily, Italy May 27, 2017.
The President, who was granted five military deferments during Vietnam, commended USA troops, saying that "you are protecting us and we will always remember that". Trump wasn't swayed by arguments from Chancellor Angela Merkel of Germany, France's President Emmanuel Macron and others to honor the Paris agreement, agreed upon in 2015 by nearly 200 nations to cut fossil fuel emissions and boost funding to ease the effects of global warming.
At the same time, several of the leaders appeared to hope this week's meeting, Trump's first, would prove a learning experience. "If he were standing here, he would tell you he feels much more knowledgable on the topic today, even though I think he's very very knowledgable in talking with leaders and having an exchange with many leaders today that have been talking about this topic for years".
"The whole discussion about climate has been hard, or rather very unsatisfactory", Merkel said after the summit.
His pending review of US climate policies has left environmentalists bracing for the possibility of bland G-7 promises that says little after years of increasingly stronger commitments to reduce reliance on fossil fuels and cut greenhouse gas emissions.