Steve Mollenkopf, the chief executive of Qualcomm, has been waiting for a phone call with news from China. It has been a long wait.

His company, which makes chips that help mobile phones communicate, has been on extended hold while the Chinese authorities review a deal that Qualcomm struck 20 months ago to buy another chip maker, NXP Semiconductors. Mr. Mollenkopf said Qualcomm had done all it could to persuade Beijing to approve the $44 billion transaction, which the companies have said will be terminated next Wednesday without regulatory consent.

But both the acquisition and Qualcomm have now become entangled in the trade war raging between the United States and China. China’s prolonged review of the deal for NXP is widely seen by analysts and trade experts as part of Beijing’s retaliation for President Trump’s tariffs on Chinese goods.

Read more from The New York Times:

Facebook to remove misinformation that leads to violence

New York City looks to crack down on Airbnb amid housing crisis

How WhatsApp leads mobs to murder in India

“We want to see it get done,” Mr. Mollenkopf, 49, said in an interview at Qualcomm’s headquarters in San Diego. When asked if his company was caught in the trade war, he said, “That’s probably accurate.”

The situation, which may be a sign of what is to come for other multinationals that also have interests dependent on China, is laced with irony. In March, Mr. Trump moved to protect Qualcomm when his administration blocked a $117 billion hostile takeover bid for the company by another chip maker, Broadcom. At the time, Mr. Trump said the deal would “impair the national security of the United States” after a government committee found that Broadcom would most likely reduce vital Qualcomm wireless research to the benefit of Chinese companies.

Now Mr. Trump may end up hurting the company that he sought to shield, in an unintended consequence of the mounting trade hostilities that his administration has spearheaded. Mr. Mollenkopf and others have said buying NXP, a Dutch chip maker, is important to helping Qualcomm move more quickly into technology for cars and other new markets.

A White House spokeswoman did not respond to a request for comment.

Mr. Mollenkopf appeared resigned to Qualcomm’s lack of options with China’s review. “We can only influence so much,” he said.

But the chief executive, a company veteran who took the top job in 2014, also struck an optimistic tone, arguing that Qualcomm can prosper without NXP because “we have a good technology road map.”

“That technology road map is going to be valuable regardless of whatever the outcome is with NXP,” Mr. Mollenkopf said.

The heart of that road map is 5G, industry shorthand for a next generation of ultrafast global cellular networks that Qualcomm has been helping to develop. Mr. Mollenkopf predicts 5G will take his company beyond its stronghold in smartphones. And since signing the deal for NXP, Qualcomm has made progress on its own in diversifying its business by selling more chips into cars, he added, with its backlog of chip orders from the auto industry recently totaling $4 billion.

In addition, Mr. Mollenkopf said, if the NXP deal does not go through, Qualcomm plans a stock buyback of $20 billion to $30 billion to help lift its stock price.

Stacy Rasgon, an analyst with Sanford Bernstein, said Qualcomm’s political stalemate with China and the question of whether the company could integrate NXP effectively had led some investors to prefer a buyback. “People just want certainty, one way or another,” he said.

The fallout from the trade war is the latest challenge for Mr. Mollenkopf, who has been on the hot seat for much of his tenure as chief executive. Qualcomm has been hurt by slower sales of smartphones, while an unusual business model that combines patent licensing with chip sales has prompted antitrust squabbles on three continents.

Qualcomm’s share price has been largely under pressure since January 2017, when its longtime customer Apple and the Federal Trade Commission filed lawsuits accusing Qualcomm of abusing its market power and patent position to charge unfairly high royalties. The company has rejected the accusations.

And Mr. Mollenkopf faces faces the possibility that Paul Jacobs, a former chairman of Qualcomm and the son of one of the company’s founders, Irwin Jacobs, may mount a bid to take the chip maker private.

More recently, after the Trump administration blocked the Broadcom bid, White House actions have been problematic for Qualcomm. In April, the administration issued an order preventing American companies from selling components to China’s ZTE after finding that ZTE violated United States sanctions involving North Korea and Iran. ZTE is a major Qualcomm customer.

Mr. Trump later softened his stance toward ZTE, which agreed to changes. The Commerce Department removed ZTE from a list of proscribed customers on Friday, enabling Qualcomm to resume selling chips to the Chinese company.

It’s unclear if China might now relent on NXP, or keep withholding approval of the deal to push back against the Trump administration’s trade tariffs. “One weapon is obviously the Qualcomm weapon,” said Robert Atkinson, president of the Information Technology and Innovation Foundation, a think tank.

China’s antitrust authority, the State Administration for Market Regulation, did not respond to a faxed request for comment. The country would be the ninth jurisdiction to complete a customary antitrust review of Qualcomm’s NXP deal; eight others, including the United States, have approved it.

An NXP spokeswoman referred to recent remarks by Richard Clemmer, the company’s chief executive, who said the chip maker continued to believe in the Qualcomm transaction.

Mr. Mollenkopf embarked on the NXP deal nearly two years ago to reduce Qualcomm’s dependence on the maturing mobile phone market. While Qualcomm primarily makes mobile chips and earns most of its profit from royalty payments from handset makers, NXP sells more than 14,000 different chips that are widely used in cars, mobile payments and other applications.

The deal, announced in October 2016, seemed ambitious from the start. NXP has nearly as many employees as Qualcomm — about 30,000 — and a tradition of operating factories, which still make some of its products. Qualcomm has always relied on other companies to make the chips it designs.

Regulatory approval was expected to take time, with the companies predicting they would not be able to close the deal until the end of 2017. But the review has dragged on even longer. In Europe and South Korea, where Qualcomm has faced antitrust challenges from regulators, the authorities won concessions to make sure the company would not unfairly exploit patents on a payment technology called near-field communications it would acquire by buying NXP.

China presented special issues. The country’s regulatory authorities have taken an activist stance on antitrust reviews in the past few years. Qualcomm gets more than half of its revenue from the country, but its relations with customers and Beijing have not always been smooth.

China’s antitrust authority previously investigated Qualcomm and found in 2015 that its patent-licensing practices violated antimonopoly laws. Qualcomm agreed to pay a settlement of $975 million.

Mr. Mollenkopf, who rose through Qualcomm’s engineering ranks and helped lead chip development efforts, said the company had endured a turbulent period. But one thing is certain, he said: There will be no extension of the NXP deal deadline beyond next Wednesday, when Qualcomm reports quarterly earnings.

“We think NXP is a great deal for us,” Mr. Mollenkopf said. “If it doesn’t get done, we also have means to create value in different ways.”