In a post published to his Truth Social platform on Thursday, former U.S. President Donald Trump called for the resignation of Intel Corp chief executive Lip-Bu Tan, the 66-year-old chip veteran accused of conflicts due to his connections with China.

“I demand that the CEO of INTEL IMMEDIATELY RESIGN,” Trump wrote. “The CEO of INTEL is highly CONFLICTED and must resign, immediately. There is no other solution to this problem.”

Intel did not immediately respond to a request for comment from TechCrunch, and the White House declined to weigh in.

The comments follow a letter sent on Wednesday by Republican Senator Tom Cotton to Intel’s board chair Frank Yeary. Cotton, who in the past has also focused fire on Tan, wrote that his “recent business ties to the Chinese government and Communist Party, and now his leadership of the U.S. company that employs the most sensitive and valuable semiconductor technology in the world, raise grave concerns about the security and integrity of Intel’s operations.”

The letter, viewed by TechCrunch, went on to list Tan’s past and current investments in Chinese tech firms. Tan “has a long history as a prolific investor in Chinese technology companies and universities,” Cotton wrote. “This history, combined with his current position at Intel, could create the appearance of impropriety that would give other countries an advantage over the United States in the race for technological superiority.”

Tan founded a San Francisco-based venture capital firm and related companies in Hong Kong that, over the years, have poured hundreds of millions of dollars into Chinese tech firms. The list includes Semiconductor Manufacturing International Corp (SMIC), China’s largest chip maker.

Tan’s past work is also under scrutiny due to the position he formerly held at Cadence Design Systems, another semiconductor tech company based in California. Cadence, which produces chip design software, last week admitted that it had sold its chip design software to a Chinese university in violation of U.S. export controls. The university, Ocean University of China, has long-standing ties to China’s military.

Shares of Intel dropped by 3 percent in pre-market trading in New York on Thursday morning after Trump’s Truth Social post.

Tan is a veteran of Silicon Valley’s chip sector and the broader tech industry. He assumed the role of Intel’s CEO in March after the company’s board voted to remove Pat Gelsinger from the position in December. Gelsinger, who had taken the reins at Intel just two years prior, was replaced by Tan, who the company’s board of directors said would lead Intel through a period of major challenges.

Intel is currently the only U.S.-headquartered company that can still produce state-of-the-art semiconductors. But it has failed so far to fully take advantage of the artificial intelligence boom in chips and could be in danger of falling further behind TSMC, a Taiwanese firm that has for the past year or more dominated the state-of-the-art chipmaking industry.

Intel is in the process of implementing a significant turnaround plan, in part to aid its semiconductor manufacturing efforts. Last year, the company was awarded $20 billion in subsidies from the federal government and a further $7 billion from California. In the same month, Intel was the recipient of a $15 billion loan from the Commerce Department to be used to expand semiconductor production in the U.S.

The loan and subsidies are part of a broader push in Washington to increase domestic chipmaking and wean U.S. manufacturers off of chip imports, in particular those coming from Taiwan and South Korea. Intel is still playing catch-up with TSMC in terms of semiconductor technology, and its new CEO, Tan, is under considerable pressure to perform.

In July, Tan said that the company needs a “significant external customer” to support the development of its next-generation manufacturing technology. Intel needs to find a large customer in order for it to be able to continue making its next-generation manufacturing tools, Tan has said. Should Intel fail to develop that external customer, and therefore be forced to stop developing next-generation technology, it would mean that TSMC has effectively become a monopoly in leading-edge chipmaking.

The issue for Intel and the U.S. government is that semiconductors are a key part of the technology industry, and losing out in the chipmaking business could mean losing out in the next tech revolution. Chips, and especially the AI chips, will be the technology used to power the next generation of artificial intelligence and automation.