The nascent U.S. liquefied natural gas export industry has been particularly vulnerable to the U.S.-China trade war, the head of the American Petroleum Institute industry group said on Tuesday, adding that he hopes negotiators will soon resolve the dispute.

Mike Sommers, the president and CEO of the American Petroleum Institute, told reporters an escalating trade dispute could harm U.S. LNG producers, as other countries move in to fill any gap.

“This is a leadership vacuum that will be filled by many of the United States’ opponents,” Sommers told reporters in a teleconference about LNG from other countries filling China’s needs if the fuel does not come from the United States, according to Reuters.

The United States is the world’s fastest-growing exporter of LNG. China, the fastest-growing importer, bought about 15 percent of U.S. LNG exports in 2017, worth about $447 million. Through much of 2018, China was on track to buy just 10 percent of the exports.

President Donald Trump imposed tariffs on hundreds of billions of dollars of Chinese imports last year and threatened to pressure Beijing more to change its practices on issues ranging from industrial subsidies to intellectual property and hacking. China has retaliated with its own tariffs.