The State Department is poised to issue a Level 4 travel advisory instructing Americans not to travel abroad and those who are already out of the country to return home or prepare to shelter in place.

The Level 4 advisory is the department’s most severe warning, and a step beyond the Level 3 warning currently in place which encourages Americans to reconsider international travel at this time.

Last week, the White House announced the suspension of most air travel from Europe to the U.S. to guard against the spread of COVID-19, and the new advisory from the State Department will continue the grim forecasts emanating from the travel industry.

New analysis from the U.S. Travel Association projects that the travel industry will lose 4.6 million jobs by the end of April and faces catastrophic losses of $355 billion as a result of the coronavirus. The non-airline travel sector is seeking $250 billion in immediate aid to avoid putting millions of Americans out of work.

“The news we have for policymakers and the public is very challenging: the 15.8 million American jobs supported by travel are directly in the crosshairs of the health crisis, and the only thing that’s going to protect them is aggressive financial relief now,” said USTA President and CEO Roger Dow. “We’re witnessing the shutdown of travel. The economic effects of that are already disastrous but could become worse and permanent unless the government acts now.”