Donald Trump on Thursday called for the immediate resignation of the new chief executive of Intel, Lip-Bu Tan, claiming the veteran semiconductor industry veteran is “highly conflicted.”

“I have just become aware that the CEO of INTEL is highly CONFLICTED and must resign, immediately. There is no other solution to this problem,” Trump wrote in a post on his Truth Social platform. The statement did not go into detail regarding Tan’s alleged conflicts of interest.

Trump’s comments came days after Republican Senator Tom Cotton sent a letter to the board chair of Intel, Frank Yeary, expressing “concern about the security and integrity of Intel’s operations” in light of Tan’s business ties to China. Cotton highlighted Tan’s long history as a serial investor in Chinese technology companies, arguing such ties could pose a potential conflict to Intel’s position as the U.S.’s preeminent advanced chipmaker.

Tan is a Silicon Valley veteran who has been active in semiconductors and venture capital for decades. His investment firm, based in San Francisco, as well as companies based in Hong Kong, have channeled hundreds of millions of dollars into Chinese technology companies in recent years. Past investments by Tan include Semiconductor Manufacturing International Corp (SMIC), China’s largest chipmaker.

Tan’s record has come under even greater scrutiny in light of his past role as chief executive of Cadence Design Systems. Cadence, a California-based company that sells chip design software, disclosed last week that it had violated U.S. export controls by selling its tools to a Chinese university with alleged military ties. The disclosure has raised new questions about Tan’s professional network and past investments just as he takes the helm of the world’s largest chipmaker.

Intel and the White House did not immediately respond to requests for comment on Trump’s post. Intel’s shares, however, fell in pre-market trading in New York on Thursday morning, dropping 3 percent after Trump’s post.

Tan took the helm of Intel in March after the company’s board ousted his predecessor, Pat Gelsinger, in December. His ascent to the top of Intel comes at a challenging time for the Silicon Valley icon, which has ceded ground to Taiwan Semiconductor Manufacturing Company (TSMC), the world’s most advanced chipmaker.

Intel, by some measures, is the most important company in the global chip race. The company is the only U.S.-based company with the capacity to make leading-edge semiconductors. However, Intel has so far been largely left out of the boom in artificial intelligence chips that is driving the latest round of the global chip race.

Intel has secured billions of dollars in government subsidies and loans to try to reinvigorate its business. The funding is part of a broader push by the Biden administration to shore up U.S. semiconductor manufacturing capacity and help end American dependence on overseas chipmakers, many of which are based in Taiwan and South Korea. But Intel has been left far behind in cutting-edge manufacturing technology, and the pressure on Tan has been on from day one.

Tan, himself, warned in July that Intel would have to stop development of its next-generation manufacturing technology unless it could secure a “significant external customer.” If Intel were to stop making advanced semiconductors, TSMC would have a monopoly on leading-edge chipmaking. For a U.S. company that has been overtaken by TSMC and with national security implications for Intel, such a development would be disastrous.

The possibility of Intel giving up on cutting-edge chipmaking has come as Tan has simultaneously implemented aggressive cost-cutting. Tan has pledged to cut costs to turn the company’s profit engine around, moves that have been met with some skepticism.

Senator Cotton’s letter, released earlier this week, also highlighted this concern, arguing Intel’s status as a recipient of taxpayer-funded subsidies puts it under greater pressure to ensure security compliance and corporate integrity. “Intel is required to be a responsible steward of American taxpayer dollars and to comply with applicable security regulations,” Cotton wrote. “Mr Tan’s associations raise questions about Intel’s ability to fulfill these obligations.”