Airport employees unload cargoes containing medical supplies at Chopin International Airport in Warsaw, Poland on March 31, 2020. A plane from China carrying protective gear for Polish medical services to fight the coronavirus epidemic has landed in Warsaw, the press office of the Polish Foreign Ministry said Tuesday in a statement. (Photo by Jaap Arriens/Xinhua)

An airport employee transports cargoes containing medical supplies at Chopin International Airport in Warsaw, Poland on March 31, 2020. A plane from China carrying protective gear for Polish medical services to fight the coronavirus epidemic has landed in Warsaw, the press office of the Polish Foreign Ministry said Tuesday in a statement. (Photo by Jaap Arriens/Xinhua)

Airport employees unload cargoes containing medical supplies at Chopin International Airport in Warsaw, Poland on March 31, 2020. A plane from China carrying protective gear for Polish medical services to fight the coronavirus epidemic has landed in Warsaw, the press office of the Polish Foreign Ministry said Tuesday in a statement. (Photo by Jaap Arriens/Xinhua)

A Boeing 787 carrying medical supplies arrives at Chopin International Airport in Warsaw, Poland on March 31, 2020. A plane from China carrying protective gear for Polish medical services to fight the coronavirus epidemic has landed in Warsaw, the press office of the Polish Foreign Ministry said Tuesday in a statement. (Photo by Jaap Arriens/Xinhua)

Airport employees unload cargoes containing medical supplies at Chopin International Airport in Warsaw, Poland on March 31, 2020. A plane from China carrying protective gear for Polish medical services to fight the coronavirus epidemic has landed in Warsaw, the press office of the Polish Foreign Ministry said Tuesday in a statement. (Photo by Jaap Arriens/Xinhua)

Airport employees unload cargoes containing medical supplies at Chopin International Airport in Warsaw, Poland on March 31, 2020. A plane from China carrying protective gear for Polish medical services to fight the coronavirus epidemic has landed in Warsaw, the press office of the Polish Foreign Ministry said Tuesday in a statement. (Photo by Jaap Arriens/Xinhua)