In the latest sign of a looming trade war, the U.S. Commerce Department has barred Chinese tech company ZTE from purchasing American parts and software for seven years.

This move comes amid escalating tensions between the world’s two biggest economies, with both governments threatening to slap hefty tariffs on each other’s imports. In March, Trump imposed a 25% tariff on aluminum and steel imports from all countries excluding Canada and Mexico. The Trump administration would later go on to exempt Argentina, Australia, Brazil, South Korea, and the EU from the tariffs, leaving China as the single-biggest remaining target. Trump also warned of an additional $60 billion in tariffs coming on other Chinese goods, which have yet to be implemented.

China quickly retaliated with $50 billion in tariff proposals of its own—and has since followed through with $3 billion of them. Then in early April, Trump threatened to implement $100 billion in…