China said the US move to close its Houston consulate this week had "severely harmed" relations and warned it "must" retaliate, without detailing what it would do.
Washington on Tuesday gave China 72 hours to close the consulate, which it said was "to protect American intellectual property and Americans' private information," a dramatic escalation of tension between the world's two biggest economies.
Chinese Foreign Ministry spokesman Wang Wenbin described the US allegations as "malicious slander" and said the "unreasonable" move had "severely harmed" relations.
"China must make a necessary response and safeguard its legitimate rights," he said, declining to specify any measures.
The South China Morning Post reported that China may close the US consulate in the southwestern city of Chengdu, while a source told Reuters on Wednesday that China was considering shutting the consulate in Wuhan, where the United States withdrew staff at the start of the coronavirus outbreak.
Hu Xijin, editor of China's Global Times tabloid, posted on Twitter: "Based on what I know, China will announce countermeasure on Friday Beijing time. One US consulate in China will be asked to close."
He had earlier said that shutting the Wuhan consulate would be insufficiently disruptive and suggested that China could cut US staff at its large consulate in Hong Kong, which he described as an "intelligence centre."
"This will make Washington suffer much pain," he wrote.
The other US consulates in China are in Guangzhou, Shanghai and Shenyang.
China has four other consulates in the United States - in San Francisco, Los Angeles, Chicago and New York - as well as an embassy in Washington.
A US law enforcement official, familiar with the reasons for the closure of Chinese consulate in Houston, said there was "not one singular incident" which led to the decision. He said the consulate was part of a "continual pattern" of suspicious or potentially illegal activities by Chinese diplomatic missions.
Republican Senator Marco Rubio, acting chairman of the Senate Intelligence Committee, described the Houston consulate on Twitter as the "central node of the Communist Party's vast network of spies & influence operations in the United States".
President Donald Trump said in answer to a question at a news briefing on Wednesday it was "always possible" other Chinese missions could be closed too.
Richard Grenell, special presidential envoy for Serbia and Kosovo who served until recently as acting director of US national intelligence, told Reuters the US strategy was "very much start with one and move on to others if need be."
"It's the escalation strategy," he said.
"The whole goal is to change the behavior of the Chinese... this is emerging as the Trump doctrine, which is very harsh actions, sanctions and isolation while at the same time always offering a chance to exit if the behavior changes."
The Wall Street Journal said US Secretary of State Mike Pompeo would deliver a speech in California later on Thursday urging allied countries and the people of China to work with the United States to change the Chinese Communist Party's behavior.
In spite of the tensions, a flight bound for Shanghai carrying US diplomats left the United States on Wednesday night, as Washington pressed ahead with its plan to restaff missions in China evacuated due to the coronavirus pandemic.
US-China ties have deteriorated sharply this year over issues ranging from the coronavirus and telecoms-gear maker Huawei to China's territorial claims in the South China Sea and its clampdown on Hong Kong.
Chinese state media editorials said the US move against the Houston consulate was an attempt to blame Beijing for US failures ahead of Trump's November reelection bid.
Opinion polls show Trump trailing his Democratic rival Joe Biden ahead of the Nov. 3 election. The candidates have appeared to compete in their campaigns over who can appear toughest towards Beijing.
Separately, the Federal Bureau of Investigation alleged in US court filings that a Chinese researcher accused of visa fraud and concealing ties to the military was now holed up in China's consulate in San Francisco.
Other Chinese researchers at US universities have also been arrested for visa fraud, according to US court filings.
Wang said China would safeguard its citizens.
"For some time, the US has held ideological bias to continuously surveil, harass and even arbitrarily detain Chinese students and scholars in the US," he said.
"We urge the US to stop using any excuse to restrict, harass or oppress Chinese students and researchers in the US"