British Prime Minister Rishi Sunak described China as the biggest challenge to the world on Sunday at the end of the G7 summit in Hiroshima, Japan.

“China poses the biggest challenge of our age to global security and prosperity,” Sunak told reporters at the G7 meeting, which ends on Sunday. “They are increasingly authoritarian at home and assertive abroad.”

The British prime minister stopped short of calling for a “de-coupling” between China and the West, but supported “de-risking,” the expression used by G7 leaders in their joint communique on Saturday.

“We will work together as the G7 and other countries to make sure that we can de-risk ourselves and the vulnerability of supply chains that we have seen from China, take the steps necessary to protect ourselves against hostile investment and do so in a way that doesn’t damage each other,” Sunak said.