OPEC Secretary-General Mohammad Barkindo expects global trade disputes to hit energy demand and eventually hurt economic growth.

Barkindo told reporters on Wednesday in Cape Town that OPEC was hopeful the “cloud of uncertainty” would ease soon.

The prospect of a trade stand-off between the United States and China triggered by U.S. President Donald Trump’s tariff threats against the world’s second-biggest economic power has caused jitters in markets across the world.

“The trade disputes that are emerging among some of the leading partners in the world will eventually hurt (global economic) growth and, by extension, demand for energy,” Barkindo said.