United Nations last night kicked off a high-level plenary meeting on addressing large movements of refugees and migrants at UN headquarters in New York.<br/><br/>World leaders are arriving for the annual confab with hopes of addressing everything from superbugs to climate change and a global anti-poverty drive that is already faltering in its first year. <br/><br/>Presidents, diplomats and their delegations must also broach impromptu items, such as North Korea's recent nuclear test. On top of that, the United States, Russia, China and other UN heavyweights must see beyond their differences and agree on who will run the world body once the incumbent, Ban Ki-moon, steps down at the end of the year.<br/><br/>Last night, the UN hosted a summit for refugees and migrants, with governments adopting a political declaration that human-rights groups have criticised as being too little, too late. A separate meeting on refugees, to be hosted by US President Barack Obama today, will probably gain more traction.<br/><br/>Tomorrow, leaders will be asked to ratify a climate change deal agreed in Paris in December, pushing it closer to the 55 ratifying States, covering at least 55 percent of global emissions, needed before it comes into force. UN officials say that deal could be sealed by early 2017. <br/><br/>The UN will launch a scheme to combat antibiotics-resistant bugs tomorrow. But, for the UN, the big 2016 General Assembly theme is the set of environmental and anti-poverty targets that were agreed last year by all 193 members, with the headline ambitions of ending poverty and hunger everywhere by 2030.