Boutros Boutros-Ghali, a veteran Egyptian diplomat who helped negotiate his country’s landmark peace deal with Israel but then clashed with the US when he served a single term as UN secretary-general, has died aged 93.

The UN chief has praised Pope Francis for framing climate change as an urgent moral imperative, saying his upcoming encyclical combined with a new round of UN climate talks provide an “unprecedented opportunity” to create a more sustainable future for the planet.