White House trade advisor Peter Navarro said Tuesday he has no knowledge of an exemption for Apple's iPhones in U.S. trade talks with China.

On Monday The New York Times reported, citing a source, that President Donald Trump told Apple CEO Tim Cook the U.S. government would not impose tariffs on iPhones assembled in China. The Times' story focused on how Cook visited both the White House and a major summit in Beijing in the last few months in an effort to soothe trade relations between the two countries.

The iPhone maker is worried Beijing will retaliate against U.S. pressure in ways that might constrain Apple's business, the Times said, citing three people familiar with the matter.

Shares of Apple traded about 1.7 percent lower Tuesday afternoon.

The company declined to comment to CNBC. Cook told CNN in an interview earlier this month he doesn't think the iPhone will get a tariff, "based on what I've been told and what I see."

Apple sells millions of iPhones in China and has 41 stores in the country.

Twenty percent of Apple's revenue is exposed to the Asian country, according to a Morgan Stanley report. Manufacturers of semiconductors, key to iPhone construction, are also the most sensitive industry to China, with 52 percent revenue exposure, the report said.

Navarro also said none of the Trump administration's negotiation efforts with Beijing have made progress on changing China's "predatory" trade practices.

China's offers shrunk throughout the talks, Navarro said. Beijing did offer to buy $200 billion in U.S. products over three to four years, he said.