Donald Trump’s top trade negotiator told him that Beijing was back-tracking on a trade deal following a round of talks last week, angering the president and leading him to threaten on Sunday to raise tariffs on Chinese goods, according to people familiar with the matter.

In talks last week in Beijing, Chinese officials told their U.S. counterparts they would not agree to a trade deal that required changes to Chinese law, the people said. China had previously agreed to change its laws in the text of the deal, they said.

The change has major implications for provisions of the deal aimed at ending a Chinese practice of forcing U.S. companies seeking to do business in the country to reveal proprietary technologies and other intellectual property.

The U.S. side, led by Trade Representative Robert Lighthizer, thought that issues around what’s known as forced technology transfer were resolved and considered the Chinese position on changing its laws to be an attempt to renegotiate, the people said. Lighthizer was angered by the move and briefed Trump.

The president then issued a pair of tweets on Sunday criticizing China and threatening to raise tariffs on about $200 billion in goods to 25 percent from 10 percent.

The people familiar with the matter asked not to be identified because the China trade talks are sensitive and have been conducted in secrecy. But official readouts last week from the U.S. and Chinese governments that depicted the latest round of talks in Beijing as productive were overstated, the people said.

Trump’s trade negotiators weren’t particularly surprised by his tweets, the people said. The White House didn’t immediately comment.

A new round of trade talks are expected this week in Washington, but it is unclear whether the Chinese government will send top officials following Trump’s tweets. A Chinese foreign ministry spokesman said on Monday that a delegation would still travel to Washington but would not say when.

Global equities tumbled and Treasury futures climbed following the tweets, which set back investor confidence the U.S. and China would soon resolve their trade war.

The S&P 500 Index fell as much as 1.6 percent on Monday before paring losses. The tweets did considerably more damage in China, where the Shanghai Composite Index sunk 5.6 percent on Monday for its steepest drop in three years, even after state-backed funds were said to step in to cushion the blow.