By Guillermo Martinez and Ana Cantero VILLARDEVÓS (Reuters) -Scorching heat hampered efforts to contain 20 major wildfires across Spain on Sunday, prompting the government to deploy an additional 500 troops from the military emergency unit to support firefighting operations.

Europe has been warming twice as fast as the global average since the 1980s, making the region more vulnerable to wildfires.

Four dead as Spain hit by worst wildfires on record in 45C heatwave - Temperatures have soared to 45C in Spain in the past fortnight - so far fires have burned over an area the size of Mallorca

Spain's worst wave of wildfires in at least two decades spread to the southern slopes of the Picos de Europa mountain range on Monday and prompted authorities to close part of the popular Camino de Santiago pilgrimage route.

The fires in Spain this year have burned 158,000 hectares or 610 square miles, according to the European Union’s European Forest Fire Information System. That is an area roughly as big as metropolitan London.

Spanish leader Pedro Sanchez promised on Sunday a "national pact" to deal with the climate emergency, as he visited a western region battling devastating wildfires."The government of Spain will work now so that in September we can have the bases of this national pact to mitigate and adapt to the climate emergency,

Drone footage shows the aftermath of wildfires that swept through Spain's Galicia region:: Verin, Spain:: The country was battling 14 major blazes driven by high winds and aggravated by heat:: The flames have consumed around 388,