GENEVA, Switzerland – Restrictions some countries have introduced in response to China's Covid-19 surge are "understandable", given the lack of information from Beijing, the head of the World Health Organization said Thursday.

WHO chief Tedros Adhanom Ghebreyesus urged China to be more forthcoming on the pandemic situation in the country.

His comments came after the United States joined several nations in imposing Covid tests on travelers from China after Beijing dropped foreign travel curbs despite a surge in cases.

The EU's health agency said however that such measures weren't warranted for the moment in the bloc.

"In order to make a comprehensive risk assessment of the Covid-19 situation on the ground in China, WHO needs more detailed information," Tedros said on Twitter.

"In the absence of comprehensive information from China, it is understandable that countries around the world are acting in ways that they believe may protect their populations.

"We remain concerned about the evolving situation and we continue encouraging China to track the Covid-19 virus and vaccinate the highest risk people.

"We continue to offer our support for clinical care and protecting its health system."

Hospitals across China have been overwhelmed by an explosion of infections following Beijing's decision to lift strict rules that had largely kept the virus at bay but tanked the economy and sparked widespread protests.

China said this week it would end mandatory quarantine on arrival, prompting many Chinese to make plans to travel abroad.

On December 21, Tedros told journalists the WHO was concerned about increasing reports of severe disease in China.

He called for detailed data on disease severity, hospital admissions and intensive care requirements.

China's National Health Commission said last week it would no longer release an official daily Covid death toll.