UN negotiators meeting in Madrid have been accused of "playing politics" while the climate crisis grows.

The talks - now in their final week - are bogged down in technical details as key countries seek to delay efforts to increase 
their pledges, observers say.

Ministers are due to arrive in the Spanish capital this week to try to secure an ambitious outcome.

US presidential hopeful Michael Bloomberg is due to attend, while Greta Thunberg will also address the meeting.