Donald Trump has called for Intel’s new CEO, Lip-Bu Tan, to resign over alleged conflicts of interest.

“THE CEO OF INTEL IS HIGHLY CONFLICTED and must resign immediately. There is no other solution to this problem,” Trump wrote in a statement on his Truth Social network on Thursday. No further details were given.

The remarks come days after a Republican senator, Tom Cotton, wrote a letter to Intel’s chairman, Frank Yeary, to express “concern about the security and integrity of Intel’s operations” given Tan’s extensive business dealings in China. In his letter, Cotton cited Tan’s long history as a major investor in Chinese tech companies, which could potentially influence Intel, the U.S. leader in advanced chips.

Tan, a Silicon Valley veteran with decades of experience in semiconductors and venture capital, has raised large sums for Chinese tech companies through his San Francisco-based investment firm as well as an affiliated fund based in Hong Kong. Tan, a Singaporean national, was an early backer of Semiconductor Manufacturing International Corp (SMIC), China’s largest chipmaker.

Tan is also the former CEO of Cadence Design Systems, a California-based semiconductor chip design software company, which last week admitted to violating U.S. export controls for selling its chip design software to a Chinese university with military ties. The export control violation at Cadence, which came just days after Tan joined Intel, has raised questions about Tan’s connections and business dealings, which appear to put him at odds with the Biden administration’s current efforts to limit China’s semiconductor industry.

Intel did not respond to a request for comment, but the White House also declined to comment. Intel’s share price was down 3 percent in pre-market trading in New York on Thursday following Trump’s post.

Tan joined Intel as its CEO in March after the company’s board of directors decided to replace its previous CEO, Pat Gelsinger, who was fired in December. Tan’s ascension to CEO comes at a critical time for the Silicon Valley-based company. Intel has long struggled to keep pace with Taiwan Semiconductor Manufacturing Company (TSMC), a global leader in chipmaking that has challenged Intel for a decade. Intel’s long-time lead in the semiconductor industry has been eclipsed by Taiwan and by TSMC, which has become the largest manufacturer of semiconductors in the world.

Intel is the only U.S.-based company still capable of making advanced semiconductors domestically. But Intel has so far failed to cash in on the current boom in artificial intelligence chips, a field that is now at the center of global competition in semiconductors.

Intel’s weakness in AI chips and its dependence on TSMC, a Taiwanese manufacturing company, is an acute national security risk to the United States at a time of political tensions between Washington and Taipei. In an attempt to help Intel compete more aggressively with TSMC and others, the company has received billions of dollars in government subsidies and low-interest loans over the past year. Washington has pledged billions more in subsidies to Intel in an effort to encourage the construction of a new domestic chip manufacturing facility in Ohio.

Intel is still playing catch-up in key areas like advanced chipmaking, with TSMC far ahead of Intel. Tan has faced pressure from the beginning to perform. In July, Tan said that Intel must find a “significant external customer” to support its advanced manufacturing technology. “If we can’t find an external customer, we will stop the development” of that manufacturing technology, Tan said in July.

If Intel were to step back from next-generation manufacturing, TSMC would be the only major semiconductor maker with a leading-edge manufacturing technology in the United States. Such a development would have major implications for the semiconductor industry and for U.S. national security.

Tan’s warning came amid an aggressive cost-cutting campaign designed to restore Intel’s profit margins, which has included job cuts and restructuring. While some investors have responded positively to Tan’s move to cut costs, they have added to growing concerns about Intel’s long-term strategy.

In his letter, Cotton wrote that Tan’s background raises questions about his ability to provide the level of security compliance Intel is required to provide as a recipient of taxpayer subsidies. “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.”

Tan’s record as an investor and entrepreneur in China and his previous leadership role at Cadence, which was acknowledged last week acknowledged violating U.S. export controls, has put Intel’s management in a difficult position.