Air travelers entering the United States are set to face tougher COVID-19 testing requirements following the discovery of the Omicron coronavirus variant, a Centers for Disease Control and Prevention (CDC) confirmed Tuesday. U.S. citizens and foreign nationals arriving in the United States will soon be required to present a negative COVID-19 test performed within one day of departure, a change from the current three days allowed for vaccinated travelers. A CDC spokeswoman confirmed to Reuters that the agency is working to modify its global testing rules for travel. “As we learn more about the Omicron variant; a revised order would shorten the timeline for required testing for all international air travelers to one day before departure to the United States,” the spokesperson said. The administration is also reportedly considering whether to require air travelers to get a second COVID-19 test within three to five days after arrival in the United States. The CDC did not provide a timeline for when …