Washington, Nov 15 : US Democrats are urging President Joe Biden to issue a mandate for all airline passengers to either show proof of full vaccination against Covid-19 or a negative test before boarding a domestic flight, according to local media reports. "This is a necessary and long overdue step toward ensuring all Americans feel safe and confident while travelling and reduce the chances of yet another devastating winter surge," Xinhua news agency quoted the reports on Sunday citing a letter signed by over 30 Democrats as saying. According to the media reports, the letter was sent to Biden on November 11 and comes as millions across the US are planning to travel during the upcoming Thanksgiving holiday which will be celebrated on November 25 this year. An estimate from the American Automobile Association said over 53 million people were planning to travel to see their loved ones for Thanksgiving this year. Of that, about 4.2 million people were expected to travel by air. The Centers for Disease Control and Prevention (CDC) has advised people to avoid taking domestic flights unless they are fully vaccinated against the virus. The White House announced last month that inbound international travellers must show a proof of full vaccination to enter the country. The Democrats who signed on the letter are urging Biden to expand that mandate to people travelling within the US so as to minimise the risk of Covid transmission after the holiday. "We applaud your adoption of vaccine requirements for international air travellers coming to the US. It is in the best interest of our nation's public health to adopt these vaccination requirements for US air travel," said the letter. The US administered over 9.5 million doses of Covid-19 vaccines in the past seven days, the highest weekly total since late May, the White House's Covid-19 data director Cyrus Shahpar announced on Saturday. Vaccinations of children ages 5 to 11, which became widely available this week, likely contributed to the total. On Sunday, the CDC updated that 226,157,226 people had received at least one dose of a Covid-19 vaccine, making up for 68.1 per cent of the whole US population. Fully vaccinated people stood at 194,951,106, accounting for 58.7 per cent of the total, while 28,571,625 others, or 14.7 per cent of fully vaccinated group, received booster shots. However, Covid-19 cases are still increasing in places like the upper Midwest, Southwest and parts of the Northeast, "hindering the nation's progress in ending a surge triggered by the highly contagious Delta variant of the coronavirus", The Wall Street Journal said in a report on Sunday. Nationally, the seven-day average of new cases appears to be edging back up after hovering just above 70,000 for several weeks, according to data from Johns Hopkins University, halting what had been a decline from the Delta-fuelled peak that began in September, the report added. As of Monday morning, the US continues to account for the world's highest number of cases and deaths at 47,074,080 and 763,092. /IANS