Commission President Ursula von der Leyen praised firefighters across the continent, as emergency services struggle to contain fires in France's south-west and in several other countries.
France's south-west region of Gironde has endured a hellish week in which more than 7,400 hectares of forest have burned and at least 10,000 people have been evacuated from their homes.
Although they were partially contained during the night, the fires continued to rage on Friday. Authorities say rain is not expected until Sunday at the earliest.
Firefighters from all over Europe have come to the aid of their French colleagues, who are unable to cope with the sheer number of new outbreaks and the re-emergence of fires that had not been completely extinguished.
European Commission President Ursula von der Leyen has praised the solidarity of "heroic" firefighters across the continent. European solidarity appears more necessary than ever in a continent plagued by drought and heatwaves.
Hundreds of European firefighters from Germany, Romania and Italy gathered on Friday to help their French counterparts in the fight against the still active fire in the Gironde and Landes departments.
"We are ready to go on the field," said Colonel Cristian Buhaiànu, head of the 77-strong Romanian detachment in the hot sun.
The operational headquarters is located a few kilometres from the fire at Landiras, where 7,400 hectares have burned since Tuesday.
"We have 1,100 firefighters present, plus an additional 361 personnel and 101 vehicles from European support. They will arrive, some arrived yesterday, like our German and Romanian friends and then our Austrian and Polish friends will arrive later today", said Ronan Léaustic, deputy prefect for Arcachon, which lies 60 kilometres south-west of Bordeaux.
A fire that broke out on Wednesday evening in the southern Ardèche department and ravaged at least 320 hectares "has been fixed", the departmental prefecture announced on Friday afternoon.
According to the EU's earth observation programme, Copernicus, large swathes of Europe and North Africa are now in "extreme danger" of catching fire.
In Portugal, flames have been engulfed the Serra Da Estrela natural park, while the glacial valley of Zezere, a World Heritage Site, has suffered irreparable losses.
More than 1,500 Portuguese firefighters remained mobilised Friday to try to put out a forest fire that has been raging for almost a week in the centre of the country, destroying some 10,000 hectares of vegetation in a natural park.
"There is still an active front that concerns us" at the confluence of the municipalities of Guarda and Celorico da Beira, said civil protection commander Miguel Cruz at a midday press briefing.
"The rest of the perimeter is more stable," he added, adding that the firefighters' ground work was supported by some 15 helicopters or water-bombing planes, including a Spanish Canadair.
The blaze is already the biggest of this summer in Portugal, devastating the Unesco-recognised world geo-park in the Serra da Estrela mountain region, which rises to around 2,000 metres.
After breaking out in the municipality of Covilha, it spread northwards to the municipalities of Manteigas, Gouveia, Guarda and Celorico da Beira.
The flames caused "irreparable damage" by destroying "unique" areas of forest, the president of the environmental association Zero, Francisco Ferreira, lamented to the public channel RTP.
With the civil protection command under fire for its management of the operations, Portuguese Prime Minister Antonio Costa said on Friday that he wanted to know "what should have been done so that the fire did not grow to this extent".
In the past week, the forest fire has injured around 15 firefighters and caused the temporary evacuation of around 20 people.
Portugal, which is experiencing an exceptional drought this year, also had its hottest July in almost a century.
Since the beginning of the year, some 78,000 hectares have already gone up in smoke, the most serious toll since the deadly fires of 2017, which claimed around 100 lives, according to the Institute for Nature and Forest Conservation.
Elsewhere, blazes continue to wreak havoc in parts of Greece, Italy and Spain.