At least 1,500 nurses worldwide have now died from COVID-19, according to the International Council of Nurses (ICN).
Howard Catton, chief executive of ICN, said that was the same number of nurses who were killed in World War I.
In August, ICN reported 1,097 nurse deaths from COVID-19. But the toll only covered 44 countries, so the true figure could be higher.
"We know in the last few days there are 1,500 nurses, tragically and sadly, who have lost their lives to this disease," Catton told Euronews.
"Nurses are angry about the lack of preparedness but they are also angry about the lack of support that they have received.
"We need to move on from the warm words to real action because none of us are going to cope and our economies won't recover if we don't keep our healthcare workers and nurses working and looking after all of us."
Catton's remark came as Spanish doctors staged their first national walkout in 25 years to protest against what they say are poor working conditions and a weak healthcare system amid the coronavirus pandemic.
But the 24-hour strike was barely noticeable in hospitals as authorities ordered a minimum staffing level of 80% and in many cases, 100% amid the spread of COVID-19.
The protest was called by the State Confederation of Medical Unions, which wants health authorities to negotiate changes in the sector.
The confederation said the coronavirus pandemic has exposed a detrimental lack of investment in the Spanish public health system in the last decades.
COVID-19 is continuing to wreak havoc across Europe and healthcare workers are among the most badly affected across the continent.
France is bracing itself for new restrictions as cases there are surging, and nearly half of the country's intensive care units are filled with coronavirus patients.
The situation is better in neighbouring Germany which may take in victims from the Netherlands and Belgium.
Watch the interview with Howard Catton in the video player, above.