China on Monday pledged to carry out countermeasures against the latest U.S. move to end special treatment of Hong Kong, portending a further escalation of already strained relations between the world's two major powers.

Chinese Foreign Ministry spokesman Zhao Lijian also lambasted the U.S. decision to leave the World Health Organization, calling it a "selfish action that would destroy international cooperation to deal with infections" with the new coronavirus.

Criticizing the United States for interfering in China's internal affairs, "Behavior that undermines the benefits of the Chinese side will be exposed to a decisive counterattack," Zhao told reporters.

Chinese President Xi Jinping (facing camera) and his U.S. counterpart Donald Trump are pictured before a photo session at a Group of 20 summit in Buenos Aires on Nov. 30, 2018. (Kyodo)

Sino-U.S. tensions have been intensifying recently over the origins of the virus, first detected in the central Chinese city of Wuhan late last year, and several other issues including trade, the WHO, Hong Kong and state-of-the-art telecommunications technology.

U.S. President Donald Trump said Friday that his administration will take steps to revoke preferential treatment of Hong Kong over the Communist-led Chinese government's perceived endeavor to erode the territory's freedoms and human rights.

On Thursday, China's parliament passed a resolution to introduce a national security law to crack down on what Beijing views as subversive activity in Hong Kong, antagonizing pro-democracy protesters in the territory and much of the international community.

Under China's "one country, two systems" policy, Hong Kong was promised it would enjoy the rights and freedoms of a semiautonomous region for 50 years following the former British colony's return to Chinese rule in 1997.

In line with the framework, the United States under a 1992 law gives Hong Kong a special status separate from the rest of mainland China on matters such as tariffs and visa issuance.

The situation has been seen as fundamental to Hong Kong's role as an attractive investment destination and global financial hub.

Zhao said legal reforms are necessary to "better implement" China's one country, two systems principle as well as to maintain Hong Kong's long-term stability and prosperity, saying, "No foreign nation has the right to interfere" in the territory

On Friday, Trump, who has attacked Beijing in an apparent attempt to gain public support prior to the November presidential election, also announced that the United States will cut ties with what he calls the "China-centric" WHO.

Trump has accused China of failing to curb the virus outbreak and share relevant information in a timely fashion, while censuring the Geneva-based U.N. agency as "a puppet for China."

Zhao said the United States "has once again revealed its true face of unilateralism and power politics," adding, "The international community has disagreed with the U.S. selfishness, avoidance of responsibility and act to undermine anti-epidemic cooperation."

"At present, the virus spread in the United States is still very serious," Zhao said. "We advise those in the United States, who still want to politicize the virus, that they should focus their thoughts and energy on fighting the outbreak at home."

The new coronavirus that causes respiratory disease COVID-19 has so far sickened over 83,000 people in mainland China and killed more than 4,600, but the increase in infections peaked in late February.

In the United States, meanwhile, around 1.7 million cases of infection have been confirmed, with the number of deaths exceeding 100,000, according to a tally by Johns Hopkins University.

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