The World Health Organization has called for "pan-European action" to tackle the root causes of climate change as Europe remains locked in the grip of a record-breaking heatwave.

Media outlets in Europe reported that the mercury hit 45 degrees Celsius in Spain on July 13 and 47 degrees in Portugal the following day. Temperatures also soared to top 40 degrees in many parts of Britain on Tuesday.

In a statement on Friday, the WHO said, "We have already witnessed more than 1,700 needless deaths in the present heatwave in Spain and Portugal alone."

The UN health agency warned the scorching summer season is barely halfway over.

The WHO noted that climate change is to blame and called on governments to work together across national borders and make "wise, far-reaching choices for the common good."