A key member of Beijing’s top advisory body issued a warning against President Donald Trump’s policies over the weekend.

Policies advocated by Trump won’t benefit the world’s largest economy, businessman Fu Chengyu said on the sidelines of the annual gathering of Asian business leaders known as the Singapore Summit.

“When countries have closed their doors, they eventually will be harmed,” he said in an apparent reference to Trump’s “America First” ideology.

It’s only when people are hurt that they rethink strategy, Fu — a member of the Chinese People’s Political Consultative Conference — continued. “Eventually, I believe they will find out that globalization is the way to lead the global economy,”

His comments come after Trump recently blocked China-backed Canyon Bridge Capital Partners’ purchase of Oregon-based Lattice Semiconductor on national security grounds.

The bilateral relationship between Chinese President Xi Jinping and the U.S. leader has been strained ever since the Republican entered office early this year, with talk of a trade war pervasive. But Fu said he doesn’t anticipate the latter scenario to materialize.

Neither Washington nor Beijing would benefit from a trade war, he noted.

A former chairman of Sinopec, the world’s biggest oil refiner, Fu also offered his take on crude prices.

Levels between $40 and $60 are sustainable for the energy world, he said. “If you want the industry to be sustainable, the price won’t be as high as most people expected in the past,” he noted.

Prices higher than $60 will just be a short-term development, he cautioned. On Friday, West Texas Intermediate traded at $49.89 a barrel while Brent stood at $55.50.