The US issued a new rule on Friday tightening visa guidelines for Chinese journalists, saying it was in response to the treatment of US journalists in China, a shift that comes amid tensions between the two nations over the coronavirus global pandemic.

The US and China have been engaged in a series of retaliatory actions involving journalists in recent months.

In March, China expelled American journalists from three US newspapers, a month after the United States said it would begin to treat five Chinese state-run media entities with US. operations the same as foreign embassies.

One day after the US verdict on the state-run entities, Beijing expelled three Wall Street Journal correspondents, two Americans and an Australian, following the publication of an opinion column that China denounced as racist.

In issuing the new regulation on Friday, the department of homeland security cited what it called China’s “suppression of independent journalism”.

The regulation, which will take effect on Monday, will limit visas for Chinese reporters to a 90-day period, with the option for extension. Such visas are typically open-ended and do not need to be extended unless the employee moves to a different company or medium.

A senior DHS official, who requested anonymity to discuss the matter, said the new rules would allow the department to review Chinese journalist visa applications more frequently and would likely reduce the overall number of Chinese journalists in the US.

“It’s going to create greater national security protections,” the official said.

The new rules will not apply to journalists with passports from Hong Kong or Macau, China’s two semi-autonomous territories, according to DHS.

Tensions between the United States and China have increased in recent months as the novel coronavirus has swept across the globe, killing more than 269,000 people worldwide to date, according to a Reuters tally.

President Donald Trump said in late April that he was confident the coronavirus may have originated in a Chinese virology lab, but declined to describe the evidence, ratcheting up tensions with Beijing over the origins of the deadly outbreak.