In 2015 the United Nations announced a radical plan to change the world. Global leaders drew up a list of 17 "sustainable development goals" to create a blueprint for a better future. Governments agreed to support the goals which cover gender equality, health provision, a good education and much more. We asked 17-year-olds from 17 different countries tell us what they think needs to change if the world is to meet those goals by 2030. This week, to coincide with the UN's Youth Forum, the Deputy Secretary General of the United Nations, Amina Mohammed, has answered questions from four of Project 17's teenagers. Yolanda Nazo, Hereiti File, Sahar Beg and Lanre Adeleye have all made programmes with the BBC about different goals. Now they get to hear from a world leader about what's being done to make change happen - and they are asked by Amina Mohammed what they are doing to make a difference. Presenter: Sana Safi Producer: Joe Kent Project 17 is produced in partnership with The Open University