President Donald Trump made clear Thursday that US tariffs against Chinese imports will take effect early Friday and that he’s prepared to sharply escalate a trade war between the world’s two biggest economies.

The administration was set to start imposing tariffs at 12:01 a.m. Eastern time Friday on $34 billion worth of Chinese imports, a first step in what could become an accelerating series of tariffs. China has promised a swift retaliatory strike on an equal amount of US goods.

After that, the hostilities could intensify: Trump said the US is ready to target an additional $200 billion in Chinese imports _ and then $300 billion more _ if Beijing refuses to yield to US demands and continues to retaliate.

That would bring the total of targeted Chinese goods to potentially $550 billion _ more than the $506 billion in goods that China actually shipped to the United States last year.

The Trump administration has argued that China has deployed predatory tactics in a push to overtake US technological dominance. These tactics include cyber-theft as well as requiring American companies to hand over technology in exchange for access to China’s market.