Republican ex-President Donald Trump called on Intel’s new chief executive officer, Lip-Bu Tan, to resign on Thursday, claiming the semiconductor industry veteran is “highly conflicted.”

The four-word statement on Trump’s Truth Social platform did not explain the basis for the ex-president’s concern. “The CEO of INTEL is highly CONFLICTED and must resign, immediately. There is no other solution to this problem,” Trump said in his post.

Trump’s criticism of Tan comes days after Republican Senator Tom Cotton sent a letter to Intel board chair Frank Yeary. In the letter, Cotton said, “I am writing to express my concern about the security and integrity of Intel’s operations in light of your decision to appoint Lip-Bu Tan as Intel’s CEO.” Cotton also raised eyebrows over Tan’s extensive business relationships in China. Tan, a Silicon Valley veteran, has a long history of investing in China’s technology companies.

In the letter to Yeary, the Arkansas senator cited Tan’s “ties to China and history of investing in China” as potential conflicts. Cotton referred to Tan’s past investments in Chinese chipmaker Semiconductor Manufacturing International Corp (SMIC), which at one time was the country’s largest.

Tan’s appointment as Intel CEO has been mired in controversy even before the company officially announced the appointment in late March. Not only was Tan criticized for his Chinese business connections, but scrutiny was also heightened on Tan because of his former leadership at California-based chip design software firm Cadence Design Systems.

Cadence last week pleaded guilty to violating U.S. export controls by selling its chip design software to a Chinese university with alleged links to the Chinese military. The revelation of Cadence’s export control violation on Friday raised fresh questions about Tan’s business ties to China.

Intel, the White House, and Tan’s new firm did not immediately respond to Reuters’ request for comment on Trump’s post on Truth Social. However, in early trading on Thursday in New York, Intel shares were down 3 percent.

Tan replaced outgoing CEO Pat Gelsinger after the company’s board voted in March to remove Gelsinger from the position. Gelsinger was removed from his role after his return to Intel, having previously served as the CEO from 2009 to 2019.

Tan assumed leadership of the Silicon Valley giant at a time when Intel’s long-term future had come under growing pressure from TSMC, the world’s largest contract chipmaker based in Taiwan.

Intel is now the only advanced chipmaker in the United States after one of its main competitors, GlobalFoundries, was forced to shut its factories in New York. Intel’s role as America’s last remaining semiconductor player has been complicated by the White House’s promotion of artificial intelligence as the next big global chip race.

Intel, already struggling to compete with TSMC’s advanced manufacturing prowess in the tech market, has mostly been sidelined in the AI chip sector, a market that Intel and other legacy chipmakers fear they are losing to start-ups like Nvidia.

Intel has, however, secured billions of dollars in subsidies and loans from the U.S. government. The federal funds are part of President Biden’s broader semiconductor strategy, the CHIPS Act, to increase domestic chipmaking and end U.S. reliance on foreign manufacturers, many of them based in Taiwan or South Korea.

In July, Tan, in an interview with The Wall Street Journal, hinted Intel may have to abandon its next-generation manufacturing technology if the company does not get a “significant external customer” on board. The “external customer” could be a reference to the U.S. government.

A move to scale back Intel’s manufacturing technology would be an industry game-changer and would give TSMC an effective monopoly in cutting-edge chipmaking, a situation with obvious implications for U.S. national security.

Tan also embarked on an aggressive cost-cutting exercise after taking over at Intel to turn around the company’s shrinking profitability. While the strategy has pleased some investors, it has added to concerns about the direction of the company in the long term.

In his letter to Intel chair Frank Yeary, Senator Tom Cotton highlighted those concerns. The Arkansas senator emphasized that as a recipient of government subsidies, Intel had to be a “responsible steward” of the American taxpayer. “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.”

Senator Tom Cotton’s Letter to Intel Chair Frank Yeary

Intel is now being forced to balance between Tan’s decades of experience in the semiconductor industry and an extensive network of business ties in Asia and China. While Tan’s professional network could be an asset in Intel’s effort to re-establish a global leadership position, his investments in Chinese firms and Cadence’s recent export control violation also allow critics to frame him as a liability in the U.S. battle with China over technological supremacy.

Trump, who in recent years has made technology and trade issues with China a key part of his political messaging, has made it clear he finds Tan’s appointment as Intel’s new CEO a step too far. Trump’s call for Tan’s immediate resignation shows that Intel’s struggles, as well as the company’s battle for global chipmaking leadership with TSMC and China, are set to become further politicized just as the U.S. is boosting efforts to challenge the Chinese semiconductor industry.