RYANAIR has offered all its more than 450 aircraft to EU governments for use for rescue flights and to transport vital medicines, personal protective equipment and emergency food supplies.
CEO Michael O'Leary said in a message to customers that the airline does not expect to be operating any commercial flights during April or May, with the bulk of its fleet grounded from yesterday.
Ryanair is Europe's largest low-cost carrier.
"At this time, no one knows how long this Covid shutdown will last," he said.
"The experience in China suggests a three-month period for the spread of the virus to be contained and reduced."
He added: "We do not expect to operate flights during the months of April and May at this time, but this will clearly depend upon government advice, and we will in all cases comply with these instructions.
"We have offered our aircraft to all EU governments, both for rescue flights and to operate essential flights for the movement of vital medicines, personal protective equipment, and if necessary, emergency food supplies."
A number of rescue flights have already been operated by Ryanair for EU governments.
The airline told the Irish Independent that those flights have been provided at cost.
"As Europe's borders become congested or closed, it's vital Ryanair plays its part to keep vital medicines and food supplies moving," Mr O'Leary added. "We are continuing to work with EU governments on rescue flights to return stranded passengers to their home country."
"While the immediate future is uncertain, it is important to remember that, like all pandemics, this crisis will pass," the airline boss said.
"Our governments and health agencies are taking unprecedented action, but they require our support, so by working together, we can help to eliminate Covid-19 and allow our lives to return to normality.
"We will do everything we can to keep our aircraft, our crews and our engineering teams operational so that when Europe defeats this Covid-19 pandemic, we are ready to return to flying."
Ryanair had cash and cash equivalents of more than €4bn as at March 12.
The group also has undrawn credit lines and almost 300 jets that it directly owns, and which are valued at between $8bn and $10bn (€7.4bn and €9.2bn).
Mr O'Leary said last week that Ryanair could survive for as long as 12 months without being able to generate any revenue.
It also operates Buzz, Lauda and Malta Air.