(The Hill) — Senate Republicans called on President Biden to restrict travel between the U.S. and China in response to a rise in respiratory infections among children in China.

Since mid-October, China has reported an increase in respiratory diseases, dubbed “White Lung Syndrome,” which officials attributed to the lifting of COVID-19 restrictions. Chinese authorities have said these infections are being fueled by known pathogens like the flu, RSV, COVID-19 and a common bacterial infection caused by mycoplasma pneumoniae.

In their letter to Biden, however, Senate Republicans repeatedly made references to a “mystery” and “unknown” illness affecting children in China.

“As you know, the Chinese Communist Party (CCP) has a long history of lying about public health crises. During the COVID-19 pandemic, the CCP’s obfuscation of the truth, and lack of transparency, robbed the United States of vital knowledge about the disease and its origin,” the letter stated.

The World Health Organization (WHO) is monitoring the situation in China and has requested information on the disease clusters among children.

“We should not wait for the WHO to take action given its track record of slavish deference to the CCP. We must take the necessary steps to protect the health of Americans, and our economy. That means we should immediately restrict travel between the United States and the PRC until we know more about the dangers posed by this new illness,” the GOP letter stated.

The letter was signed by Republican Sens. Marco Rubio (Fla.), J.D. Vance (Ohio), Rick Scott (Fla.), Tommy Tuberville (Ala.) and Mike Braun (Ind.).

Health officials have so far said there is no cause for alarm.

Centers for Disease Control and Prevention (CDC) Director Mandy Cohen told lawmakers this week that statements from China regarding the cause of the illnesses have been corroborated by both a CDC office and European Union partners.

“We believe there is no new or novel pathogen,” she said. “These are related to existing pathogens — COVID, flu, RSV” and mycoplasma, a bacterium that can infect the lungs.

Maria Van Kerkhove, acting director of the WHO’s department of epidemic and pandemic preparedness and prevention, recently noted in an interview with Stat that the wave of disease being seen in China is not as high as what was observed in 2018 to 2019 before the COVID-19 pandemic.

“We asked if anything new was detected, any new variants, any new subtypes? And the answer was no. We asked if [they] have seen any unusual disease presentations for these pathogens. And they said no. And then they gave us an overview of the burden in the health care facilities, and their hospitals are not overwhelmed,” said Van Kerkhove.