Former US president Donald Trump on Thursday called on the CEO of Intel, Lip-Bu Tan, to resign immediately, citing alleged conflicts of interest.

“Irrefutable! The CEO of INTEL is highly CONFLICTED and must resign immediately. There is no other solution to this problem,” Trump tweeted on his Truth Social media platform. He did not elaborate on what he meant by Tan being conflicted.

Tan, a veteran semiconductor industry executive, recently assumed the top leadership position at Intel, replacing a predecessor that the company’s board fired last December.

Republican Senator Tom Cotton earlier this week wrote to Intel board chair Frank Yeary to express “concern about the security and integrity of Intel’s operations” if Tan stays on as Intel’s CEO. Tan “has been an active and prolific investor in Chinese technology companies for over three decades and currently is the controlling shareholder of a venture capital firm with major operations in Hong Kong and China,” Cotton said in his letter.

Intel’s Chief Executive Officer for the past three decades, Tan has directed billions of dollars into Chinese tech companies as the head of an investment firm based in San Francisco and Hong Kong. In a recent letter to the chair of Intel’s board, Sen. Tom Cotton raised concerns about a potential conflict of interest involving Tan.

Tan’s past investment in a Chinese tech firm, Semiconductor Manufacturing International Corp (SMIC), China’s largest chipmaker, has not helped to allay fears about his ability to steer Intel, the US’s most advanced chipmaker, in the right direction.

Tan is also a former CEO of Cadence Design Systems, a California-based chip design software company. Cadence in June said it had violated US export controls when it sold its chip design tools to a Chinese university with “current or past affiliations with the Chinese military.”

Tan was named as the new CEO of Intel last week after the board of the world’s largest chipmaker in March announced he would replace Pat Gelsinger, who the board decided to replace.

Intel is at a critical stage in the global race to dominate the technology needed to power the artificial intelligence (AI) revolution. The company was able to hold its own against TSMC in cutting-edge microchip manufacturing for a long time, but the tables have turned recently.

Intel is now a distant third in the race to develop leading-edge chipmaking capacity for AI, behind TSMC and its archrival Nvidia. The semiconductor firm’s share price fell 3% after Trump’s comments. In New York on Thursday, Intel declined to comment on Trump’s statement, and the White House also declined to comment.

Tan was appointed CEO in a boardroom coup, which is an “internal battle” that was partly set in motion by the board’s decision in December to fire Gelsinger. He stepped in to replace Gelsinger after Intel’s board voted for the shake-up in March.

Tan’s appointment as CEO is seen as an effort to keep the company stable while underperforming, but with a dramatic slump in its share price in recent years. Tan’s appointment is seen as an attempt to reverse the stock’s decline by restoring profitability.

In July, Tan warned the company might have to stop developing its next-generation chipmaking technology unless it found a “significant external customer.” This would put the Taiwan Semiconductor Manufacturing Company (TSMC) in a position of having a monopoly in leading-edge chipmaking, with implications for the semiconductor industry and US national security. The US government is worried about TSMC’s position as a monopoly.

Intel’s technology is seen as vital to the US’ competitiveness in AI, which has emerged as the next big thing in the global chip race. AI is used in everything from self-driving cars to cloud computing. Intel, which is based in Santa Clara, California, was once the world’s most valuable chipmaker but has since been eclipsed by TSMC.

The company’s share price has fallen sharply since the start of the year, and it is now worth less than half as much as it was at its peak. The company has been forced to cut jobs and reduce its dividend to shareholders.

Intel has also lost market share to TSMC, which is based in Taiwan. TSMC is the world’s largest maker of semiconductors, and it has a dominant position in the manufacturing of leading-edge chips.

Intel has received billions of dollars in government subsidies and loans to help it compete with TSMC. The company has been given $20 billion in subsidies and loans by the US government, and it is eligible for $15 billion more.

The US government has been subsidizing Intel since 1981, when it started giving the company tax breaks. The company has also received billions of dollars in government loans.

In the past, Intel was able to use its subsidies and loans to invest in new technologies and keep its share price high. But now, with TSMC eating into its market share, Intel is having a harder time justifying its high valuation.

Intel is in a bind: it needs to find a new CEO, and fast. But finding a successor to Tan will not be easy. The company has a history of instability, and it is unclear who will be able to take the company in a new direction.

One possibility is that Intel will try to find a new CEO from outside the company. This would be a departure from Intel’s past practice of promoting CEOs from within. But it is not clear whether this would be successful.

Another possibility is that Intel will try to return to Gelsinger. Gelsinger was fired in December after he tried to oust then-CEO Brian Krzanich from power. But Gelsinger has his own problems: he is under investigation by the Securities and Exchange Commission for insider trading.

Intel’s future is uncertain, but one thing is clear: the company needs a new CEO. The sooner Intel finds one, the better.