TAORMINA, Italy (Reuters) - U.S. President Donald Trump expects a tough debate over trade and climate change with other Group of Seven leaders at their forthcoming summit, White House economic adviser Gary Cohn said on Thursday.

An Italian Army soldier patrols as a man walks through a metal detector in Taormina where leaders from the world's major Western powers will hold their annual summit, Italy, May 24, 2017. REUTERS/Guglielmo Mangiapane

Trump and the leaders of Japan, Canada, Germany, France, Britain and Italy are due to hold two days of talks in Sicily, with the U.S. president expected to put a firm emphasis on the importance of domestic economic growth.

His G7 counterparts are particularly concerned that he might follow through on a campaign pledge to promote a protectionist agenda, and might also walk away from U.S. commitments to cut greenhouse gas emissions under the 2015 Paris Agreement.

Speaking to reporters on a flight bringing Trump to Sicily, Cohn said both issues would feature at the meeting.

“We will have a very robust discussion on trade and we will be talking about what free and open means,” he said.

“What the president means by free and open is, we will treat you the way you treat us, meaning if you don’t have barriers to trade or you don’t have tariffs, we won’t have tariffs.”

He also predicted a “fairly robust discussion” on climate change, saying the president, who once dismissed global warming as a hoax, would only make his mind up about the Paris Agreement once he returned to Washington.

Cohn said Europeans had made more progress in curbing emissions than the United States and suggested that if U.S. industries tried to catch up too quickly, it might prove costly.

“Look, we believe in the environment, too. We believe in clean air. We believe in clean water,” he said. “But we also believe in economic growth. We believe in bringing manufacturing back to the United States, so we have to balance that. ... If those things collide, growing our economy is going to win.”

During his election campaign, Trump promised to revive the ailing U.S. coal industry and scrap environmental regulations introduced by the Obama administration. However, Cohn acknowledged that the energy mix was changing.

“Coal doesn’t even make that much sense anymore as a feedstock,” he said. “Natural gas, which we have become an abundant producer, which we’re going to become a major exporter of, is such a cleaner fuel.”

Turning to other likely discussions at the G7, Cohn said: “Terrorism is going to be a very big topic.” He added that the leaders would also discuss cyber security, North Korea, Afghanistan, Pakistan and Russia.

He said NATO leaders on Thursday in Brussels had raised the issue of sanctions imposed by the West on Russia after it annexed Crimea in 2014.

Asked whether Washington wanted to extend the financial curbs, Cohn said: “I think the president is looking at it. Right now, we don’t have a position.”