The head of the UN has warned world leaders that nations are "gridlocked in colossal global dysfunction" and are not ready or willing to tackle the challenges that threaten the future of humanity - and the planet."Our world is in peril - and paralysed," said United Nations secretary general Antonio Guterres.Speaking at the opening of the General Assembly's annual high-level meeting, he emphasised that hope remained, but his remarks reflected a tense and worried world.

The head of the UN has warned world leaders that nations are "gridlocked in colossal global dysfunction" and are not ready or willing to tackle the challenges that threaten the future of humanity - and the planet."Our world is in peril - and paralysed," said United Nations secretary general Antonio Guterres.Speaking at the opening of the General Assembly's annual high-level meeting, he emphasised that hope remained, but his remarks reflected a tense and worried world.