SHENZHEN, China — Not Apple. Not Huawei. The first casualty of the high-tech cold war between the United States and China might be the biggest electronics maker you’ve never heard of.

The Chinese firm ZTE said on Wednesday it had ceased “major operating activities” after the Trump administration banned the company last month from using components made in the United States. With manufacturing halted at the ZTE plant in Shenzhen, factory workers have been getting called in for training sessions every other day or so — a snooze, they say. The rest of the time, they loaf around in nearby dorms.

Trading in the company’s shares has been suspended for weeks. Staff members have been instructed, in new guidelines reviewed by The New York Times, to reassure anxious clients, while being sure to avoid discussing with them the American technology from which the firm is cut off for the next seven years.

One of China’s most internationally successful technology suppliers, with about $17 billion in annual revenue, ZTE is facing a death sentence. The Commerce Department has blocked its access to American-made components until 2025, saying the company failed to punish employees who violated trade controls against Iran and North Korea.