At Huawei, the Chinese tech titan whom American officials have identified as a national security threat and persistently undermined, sales are falling rapidly.

The company said Friday that its shrinking smartphone business resulted in total revenue for the first half of the year falling nearly 30 percent year over year to about $ 50 billion. However, the net profit margin was 9.8 percent compared to 9.2 percent in the previous year.

As a closely managed company, Huawei is not legally required to report its profits. It only publishes a small sample of financial results and not quarterly.

“Our goal is to survive, and to do it sustainably,” said Eric Xu, one of Huawei’s vice chairmen, in a statement on Friday.

In recent years, Huawei’s ability to work with the international computer chip industry has been limited due to a number of rules imposed by the Trump administration. It has become extremely difficult for the company to make the cutting-edge phones that made it a global goliath not so long ago. Huawei denies that its products threaten a nation’s security.

The US sanctions also prevent Huawei devices from running Google’s most popular apps. That has been selling customers outside of China for some time.

But even within China, where many Google apps have long been blocked, Huawei’s mobile phone business is falling rapidly. According to market research company Canalys, Huawei was not one of the five best-selling cell phone brands in China for the first time in over seven years. The top 5 in sequence were Vivo, Oppo, Xiaomi, Apple and Honor.

Honor was a brand owned by Huawei until it was spun off late last year to get out of US restrictions. That contributed to the decline in Huawei smartphone sales, said a company spokesman.