Italy's environment minister, Gian Luca Galletti, says the United States and the rest of the G-7 are far apart on the Paris Climate Agreement and will remain so.
Galletti is hosting other Group of Seven environment ministers for two days of talks in Bologna.
He said despite the policy split with the U.S., talks will take place on all matters concerning the global environment, including ways to clean up the polluted oceans.
"The international community is awaiting for our message," Galletti said, calling it one of sustainable development, ecology and serving the world population.
U.S. Environmental Protection Agency chief Scott Pruitt appeared briefly at the Bologna talks. He had to return to Washington for a Cabinet meeting. But he tweeted that he "spent meaningful time" with the G-7 ministers.
"Engagement is essential to protecting and using our natural resources." Pruitt said.
The other G-7 ministers expressed disappointment at President Donald Trump's decision to pull the U.S. out of the Paris Climate Accord, which seeks to limit carbon emissions and reduce the rising global temperatures.
Trump calls the pact unfair to the U.S., saying it would hurt the economy while doing next to nothing to prevent global warming.
His decision has been met with worldwide condemnation, including from within the U.S. itself. Many local governments pledge to carry out the provisions of Paris with or without the Trump administration.
Trump has proposed renegotiating the Paris accord. But other world leaders say that would be impossible.