Aviation industry groups are urging the federal government to quickly address the impact of the coronavirus on airlines, saying the current economic environment is not sustainable.

Airlines for America (A4A) and others in the aviation industry wrote to the Treasury Secretary Steven Mnuchin Steven Terner MnuchinLawmakers fear voter backlash over failure to reach COVID-19 relief deal United Airlines, unions call for six-month extension of government aid House Democrats plan to unveil bill next week to avert shutdown MORE and congressional leadership on Thursday requesting immediate action.

“The breadth and immediacy of the need to act cannot be overstated. It is urgent and unprecedented,” the letter reads.

ADVERTISEMENT

The letter comes as the State Department issued a level four travel advisory to all countries on Thursday, instructing Americans not to travel internationally and calling for U.S. citizens abroad to return home.

On Monday, the airline industry through A4A requested $50 billion in federal assistance in the form of grants, loans and tax relief. President Trump Donald John TrumpUS reimposes UN sanctions on Iran amid increasing tensions Jeff Flake: Republicans 'should hold the same position' on SCOTUS vacancy as 2016 Trump supporters chant 'Fill that seat' at North Carolina rally MORE has vowed to help the airlines, but has not explicitly committed to the full request.

U.S. airlines have also taken drastic steps to cut back on flights in recent weeks. Passenger carrier bookings for the next few months are down 100 to 200 percent, and cancellations are rapidly outpacing new bookings, according to the industry letter.

The letter stressed that the airline industry does not want to furlough employees, but retain them so they’re ready when travel returns to normal.

“What appeared to be a distant possibility just weeks ago has come to the forefront; we now face legitimate liquidity concerns and questions about our ability to meet ongoing debt obligations,” the letter reads.

Along with A4A, the letter was signed by the Air Line Pilots Association, Airport Restaurant & Retail Association, Association of Flight Attendants-CWA, International Air Transport Association, National Air Carrier Association and the Travel Technology Association, among other groups.

ADVERTISEMENT

Other industries are also seeking relief because of quarantines and closures due to the coronavirus.

The franchise industry, through the International Franchise Association on Thursday asked for the creation of a $300 billion fund to provide liquidity to franchises struggling through the coronavirus pandemic and the manufacturing industry, through NAM, asked for the creation of a $1.4 trillion fund for loans to provide liquidity to manufacturers and small businesses.

The retail industry, through the National Retail Federation, asked for a direct, government-based loan program, and the restaurant industry, through National Restaurant Association, called for financial relief, loans and tax measures to help it combat the crisis.

Earlier this week, the tourism industry, through the U.S. Travel Association and the American Hotel and Lodging Association, called for $150 billion in overall relief.