The world's two biggest economic powers threaten to create a "big rupture" in geopolitics, but "we are not there yet," UN Secretary-General António Guterres tells Ian Bremmer. In an interview for GZERO World, the leader of the world's best-known multilateral organization discusses the risks involved as the US and China grow further apart on key issues.

Watch the episode: UN Secretary-General António Guterres: Why we still need the United Nations