World leaders will start trickling into New York on Tuesday for the opening of the United Nations General Assembly, but the big names, including President Donald Trump, won't show up to U.N. Headquarters until next week. 

A new report from the UN's nuclear watchdog expresses "grave concern" that North Korea is continuing to develop its nuclear program, despite the regime's commitment to work towards denuclearization following June's summit in Singapore.

This week, in pointed testimony, President Trump’s new U.N. Ambassador Nikki Haley sparred with the Russian Ambassador during a vote on a resolution intended to hold individuals accountable for chemical weapons attacks in Syria.

The Islamic State of Iraq and Syria (ISIS) claimed responsibility for the attacks, saying its extremists opened fire in the airport and "several of them" detonated suicide belts.