WASHINGTON—A broad push by Trump administration hard-liners to stem the flow of high-tech exports to China—even if doing so means limiting the market access of major U.S. companies—hit a hurdle Tuesday: President Trump himself.

In a series of tweets, Mr. Trump denounced efforts promoted by some within the White House and Commerce Department to halt the export of controlled technologies—including jet engines and semiconductors—to China, out of concern the products could be pirated and used to undermine U.S. commercial advantage in those sectors.

“We don’t want to make it impossible to do business with us,” Mr. Trump tweeted. “That will only mean that orders will go to someplace else.”

The tweets followed a Wall Street Journal report over the weekend that officials within the administration were pushing to halt shipments of jet engines co-produced by General Electric Co. to China. The engines were designed for the Comac 919, a new commercial airliner that China hopes will grow to rival offerings from Boeing Co. and Airbus SE.

Officials are also considering changes to what is known as the foreign direct product rule, aimed at limiting the use of U.S. technology in military and national-security functions. The changes would require semiconductor manufacturers to obtain export licenses to use U.S. equipment when producing chips for Huawei Technologies Co. of China, people familiar with the discussions said.