Two months after DeepSeek, China’s artificial intelligence star, rattled Washington and shook Wall Street, U.S. officials are taking steps to crack down on the Chinese start-up and its support from America’s leading chip maker, Nvidia.

The Trump administration this week moved to restrict Nvidia’s sale of A.I. chips to China. It also is weighing penalties that would block DeepSeek from buying U.S. technology and debating barring Americans’ access to its services, said three people with knowledge of the actions who spoke on the condition of anonymity.

Congressional leaders are also putting pressure on Nvidia. On Wednesday, the House Select Committee on the Chinese Communist Party, which focuses on national security threats from China, opened an investigation into Nvidia’s sale of chips across Asia. It is trying to assess whether the U.S. chip maker knowingly provided DeepSeek with critical technology to develop A.I., potentially in violation of U.S. rules.

It is the first congressional investigation into Nvidia’s business. It comes as the Trump administration wrestles with how to carry out a Biden-era rule that limits the number of A.I. chips that companies can send to different countries.

The attacks on DeepSeek and Nvidia are an outgrowth of fear in Washington that China could leapfrog the United States in A.I., which would have wide-ranging implications for national security and geopolitics. If China took the lead, it could more quickly use A.I. systems to design next-generation weapons like autonomous missiles and drones. It also could persuade other countries to use its technology for their network of A.I. systems and infrastructure, weakening U.S. influence across the world.