Police rounded up more than 1,400 protesters on Wednesday as Russians in dozens of cities took part in rallies organised by allies of hunger-striking Kremlin critic Alexei Navalny over his failing health in jail.

In other news, Joe Biden unveiled the goal to cut emissions by 50 per cent-52 per cent from 2005 levels at the start of a two-day climate summit kicked off on Earth Day and attended virtually by leaders of 40 countries including big emitters China, India and Russia.

Watch this episode of World Today to know more.