US Democrats are urging President Joe Biden to expand COVID-19 vaccine requirements for international air travelers to people traveling within the United States so as to minimize the risk of spikes in COVID-19 cases after the Thanksgiving holiday.

NEW YORK - Democratic lawmakers are urging US President Joe Biden to require that all airline passengers either show proof of full vaccination against COVID-19 or a negative coronavirus test before boarding a domestic flight, reported Business Insider on Sunday.

"This is a necessary and long overdue step toward ensuring all Americans feel safe and confident while traveling and reduce the chances of yet another devastating winter surge," said a request letter signed by more than 30 Democrats and sent to Biden on Nov 11.

The letter came as millions plan to travel for the upcoming Thanksgiving holiday. An estimation from the American Automobile Association said over 53 million people were planning to travel to see loved ones for Thanksgiving this year. Of that, about 4.2 million people were expected to travel by air.

The US Centers for Disease Control and Prevention (CDC) has advised people to avoid taking domestic flights unless they are fully vaccinated against the coronavirus. The White House announced last month that international travelers coming into the United States must show proof of full vaccination to enter.

The Democrats who signed on the letter are urging that Biden expand that mandate to people traveling within the United States so as to minimize the risk of spikes in COVID-19 cases after the holiday.

"We applaud your adoption of vaccine requirements for international air travelers coming to the United States. It is in the best interest of our nation's public health to adopt these vaccination requirements for US air travel," said the letter.