Deutsche Lufthansa AG management apologized for the disruptions and cancellations bedeviling the global aviation industry and cautioned the situation won’t improve in the near future as carriers and airports struggle to rebuild operations from the pandemic slump.

In a letter sent overnight to customers, Europe’s biggest airline group laid out the causes of the chaos, from a lack of personnel to the war in Ukraine. The carrier said global aviation is reaching the limits of available resources, frustrating airline efforts to recover losses after the coronavirus burst a decades-long boom in travel.

“We can only apologize to you for this,” Lufthansa said in the statement. “In the coming weeks, as passenger numbers continue to rise, be it for leisure or business travel, the situation is unlikely to improve in the short term.” 

Germany’s flagship airline has cancelled a total of 3,100 flights after a wave of coronavirus infections worsened staffing shortages, adding to Europe’s travel chaos as the crucial summer vacation period gets under way. Having let go of thousands of employees during the pandemic, airlines and ground operations at airports are struggling to meet resurging travel demand. Lufthansa said the industry’s racing to rehire thousands of employees, though the push will only have a stabilizing factor this coming winter.

The war in Ukraine has restricted available airspace in Europe, prompting “massive bottlenecks in the skies” and additional delays, Lufthansa said. To help address capacity restraints, Lufthansa said in a separate release yesterday that it’s bringing back some of its Airbus A380 superjumbos that had been mothballed during the pandemic. 

In addition to staffing shortages, some other airlines and airports are wrestling with labor disputes as workers demand higher wages to help offset the soaring cost of living. Ryanair Holdings Plc workers staged walkouts in countries including Spain, Italy and France over the weekend. British Airways check-in staff have threatened strikes at London Heathrow Airport.