WASHINGTON (REUTERS) - Major US aviation, travel and aerospace groups on Monday (March 8) joined airline unions in urging the Biden administration to help establish temporary Covid-19 health credentials to boost travel, which has been hard-hit by the coronavirus pandemic.

In a letter to the White House Covid-19 recovery coordinator Jeff Zients, trade group Airlines for America, the US Chamber of Commerce, the US Travel Association and 24 other groups urged the administration to work with industry to "quickly develop uniform, targeted federal guidance for temporary Covid-19 health credentials (CHC) covering both tests and vaccinations."

The groups also said "Covid-19 vaccines should not be a requirement for domestic or international travel."

The World Health Organisation and the International Civil Aviation Organisation "are working closely to identify the necessary information that would be contained in a medical record and a travel document," the letter noted, asking the administration "to proactively develop a roadmap for the roll-out of recommended travel documentations and build a system supporting CHCs that verify both testing and vaccination records."

The groups added the credentials could "encourage more widespread adoption of processes to verify testing and vaccination records, from sports arenas to restaurants, business meetings, theme parks, and more."

The White House did not immediately comment.

The push came as the US Centres for Disease Control and Prevention (CDC) on Monday said tens of millions of Americans who have been vaccinated for Covid-19 should not travel, a blow to the airline and travel industries that have been battered by the pandemic.

"We are really trying to restrain travel at this current period of time," CDC Director Rochelle Walensky told reporters, saying the agency has not changed its guidance that all Americans should avoid travel. "Every time we have a surge in travel, we have a surge in cases in this country," she said.

Many Americans are not heeding CDC's advice. The Transportation Security Administration said nearly 1.3 million people were screened at US airports on Sunday, the second-highest day in 2021 but down 40 per cent over pre-Covid levels.

The Biden administration has taken steps to reduce international travel and mandated masks in nearly all forms of public transit.