“This would be another step in ratcheting up the pressure,” said Michael Pillsbury, a China scholar at the Hudson Institute who said he raised the concept of investment restrictions with the White House after negotiations with China broke down in the spring.

“One swallow does not make a summer,” Mr. Pillsbury said, quoting a proverb. “But these gestures are now more and more numerous.”

Michael Pillsbury, a China scholar at the Hudson Institute who informally advises the White House, said that Mr. Trump had been considering more draconian options, but settled on the higher tariffs in hopes that negotiations with China would proceed.

“The U.S. government has to be careful not to do things that could be portrayed as inciting riots,” said Michael Pillsbury, a China expert at the Hudson Institute and an informal adviser to the president.

‘Hong Kong Thing’ Is ‘Very Tough,’ but Trump Doesn’t Criticize China Michael Pillsbury, said “The

NYT Trump Says U.S. Will Hit China With More Tariffs – “Tariff Man is alive