EU countries are stepping up their help to Greece to fight forest fires devastating its mainland and some islands, the European Commission said on Monday as it coordinated the assistance.

A local uses a megaphone as others observe a large forest fire approaching the village of Pefki on Evia (Euboea) island, Greece's second largest island, on August 8, 2021. (Photo: AFP)

There are now nine planes, 1,000 firefighters and 200 vehicles deployed by European Union states, a statement said.

France, Germany, Poland, Austria and Slovakia added resources and were sending extra fire fighting units, adding to ones already in Greece from France and other EU nations.

In addition, EU help has gone to battle fires that are also burning in Italy as well as in neighbouring non-EU countries North Macedonia, Albania and Turkey, the commission said.

"We are mobilising one of Europe's biggest ever common firefighting operations as multiple fires affect several countries simultaneously," the EU commission for crisis management, Janez Lenarcic, said.

"I am very thankful to all the countries who have offered help for their tangible solidarity. Our thoughts are with all those affected and with the first responders who are risking their lives to battle the fires."