A top Chinese trade negotiator defended his country’s investigation into FedEx, the Memphis-based courier, as “understandable” as he reiterated vague warnings that China would punish those who hurt the nation’s companies for political reasons.

FedEx this week became the latest firm to be entangled in the sharply escalating U.S.-China trade war after Huawei accused it of diverting packages intended for Chinese recipients to the United States.

FedEx said there was no “external pressure” to misroute the packages amid speculation it was related to recent U.S. sanctions against the beleaguered Chinese tech giant. The courier said in a statement that the incident was a mistake and agreed to cooperate with the Chinese probe.

The FedEx investigation, disclosed by state media on Saturday shortly after the Chinese government announced a blacklist of “unreliable” foreign companies and individuals, raised fears that American companies and executives in China would come under increasing regulatory scrutiny or face punishment as the trade standoff turns acrimonious.

Wang Shouwen, a vice minister of commerce, declined on Sunday to name names on the blacklist. He said “everybody doesn’t need to worry” about facing retaliatory Chinese action “if they respect Chinese laws.”

“The entities list targets those who violate market principles and cut off business for noncommercial reasons to hurt Chinese companies and Chinese national security,” Wang said.

He told reporters that specific punishments for companies on the “unreliable” list would be announced at a later time. 

Wang, a member of the Chinese team shuttling between Beijing and Washington until trade talks collapsed last month, declined to say whether President Trump and his counterpart Xi Jinping would meet later this month in Japan on the sidelines of the Group of 20 summit of industrialized nations.

Officials on both sides see a face-to-face meeting at the Osaka summit as the best chance to halt or reverse the alarming slide in relations between the two powers.

But the chances of a productive meeting — or of a meeting at all — appear slim after Trump signed an executive order that prohibited U.S. firms from doing business or selling components and software to Huawei, a move that could cripple and humiliate an iconic Chinese company.

In retaliation, China has threatened to cut off exports of rare earth elements used in electronics manufacturing to the United States.

It’s not clear what would bring the two sides back to the negotiating table.

The Chinese have dug in to their position that the Americans were wholly responsible for the breakdown in talks in May. U.S. officials say Chinese negotiators stunned them when they backtracked on practically all the significant commitments they had made in earlier rounds of talks.

The backtracking persuaded Trump to proceed with raising tariffs on $200 billion worth of Chinese goods, administration officials said.

Wang, the Chinese negotiator, dismissed Washington’s claims Sunday as he unveiled a position paper from his ministry that declared: “The U.S. government should bear the sole and entire responsibility for this severe setback” to trade talks.

Back-and-forth revisions and adjustments until the last minute are part of any normal negotiating process, Wang said, so allegations of “backsliding” are groundless.

“Nothing is agreed until everything is agreed,” he told reporters, switching to English to make his point.