WASHINGTON (Reuters) - A coalition of airline, travel and aerospace industries and union and airport groups on Friday urged U.S. President Joe Biden not to impose new COVID-19 testing requirements for travelers on domestic flights. The federal government has been mulling additional measures to fight the spread of the coronavirus and officials said this week health agencies are “actively looking” at such testing. The industry, airport and union groups said in a letter to the White House that requiring tests before domestic air travel “is unwarranted.” It would “disproportionately prevent low-income travelers and rural Americans in small communities from travel,” said the International Air Transport Association, Airlines for America, U.S. Travel Association, Aerospace Industries Association and aviation union and airport groups. Globally, countries are adding new travel restrictions, requirements and bans amid fears over the spread of a more contagious and potentially vaccine-resistant coronavirus variant first identified in South Africa. The first U.S. cases were detected in South Carolina on Thursday. This week, the United States implemented mandatory COVID-19 testing for nearly all arriving international passengers and added South Africa to its ban of entry of non-U.S. citizens arriving from most of Europe and Brazil. Airlines support testing for international flights as a way to safely restart travel, which has been crushed by the pandemic. CEOs have said domestic testing requirements could cause logistical havoc and further reduce demand. U.S. Centers for Disease Control Director Rochelle Walensky told CNN on Wednesday “that now is not the time to be traveling period, internationally or domestically.” Congress may approve more funding for testing “for high risk activities” including travel and domestic flights, she said. Securing a COVID-19 test can take days in many places and can be costly without health insurance. There are currently around 1.5 to 2 million daily tests, according to the COVID Tracking Project. That isn’t enough to contend with daily U.S. air passengers, JetBlue Airways Chief Executive Robin Hayes said. Over one million people could be flying daily in the busy March period and “we’d have to increase the testing capacity by between 50-100% to cope with that.”