COP26: Was US President Biden sleeping or just resting his eyes?

Video footage has emerged of Joe Biden sitting with his eyes closed at the COP26 climate change summit.

The US president is among the world leaders who have travelled to the event – which he has called an "incredible opportunity" – in Glasgow.

But was he sleeping or just resting his eyes?

More on the climate summit:

The COP26 global climate summit in Glasgow in November is seen as crucial if climate change is to be brought under control. Almost 200 countries are being asked for their plans to cut emissions, and it could lead to major changes to our everyday lives.