Facing an escalating nuclear threat from North Korea and the mass flight of minority Muslims from Burma, world leaders are gathering at the United Nations to tackle these and other tough challenges - from the spread of terrorism to a warming planet.
United States President Donald Trump and France's new leader, Emmanuel Macron, will be closely watched as they make their first appearance at the General Assembly. They will be joined by more than 100 heads of state and government, including Zimbabwe's President Robert Mugabe, one of Africa's longest-serving leaders who is said to be bringing a 70-member entourage.
While Trump's speeches and meetings will be closely followed, it will be North Korea, which Secretary-General Antonio Guterres calls "the most dangerous crisis that we face today", that will be most carefully watched. No official event addressing Pyongyang's relentless campaign to develop nuclear weapons capable of hitting the US is on the UN agenda, but it is expected to be the No. 1 issue for most leaders.
Not far behind will be the plight of Burma's Rohingya Muslims, victims of what Guterres calls a campaign of ethnic cleansing that has driven nearly 400,000 to flee to Bangladesh in the past three weeks. The Security Council, in its first statement on Burma in nine years, condemned the violence and called for immediate steps to end it. British Foreign Secretary Boris Johnson was to host a closed meeting on the crisis today, and the Organisation of Islamic Co-operation's contact group on the Rohingyas is scheduled to meet tomorrow.
Guterres said leaders would also be focusing on a third major threat - climate change. The number of natural disasters is on the rise and he pointed to unprecedented weather events in recent weeks from Texas, Florida and the Caribbean to Bangladesh, India, Nepal and Sierra Leone.