UNITED NATIONS, Sept. 20 (Xinhua) — The 71st session of the UN General Assembly on Tuesday opened its annual high-level General Debate at the UN headquarters in New York, with a focus on pushing for the world's sustainable development.

UN member states should strengthen efforts to bring the Paris Agreement on climate change into force by the end of the year for building a world of sustainable growth, UN Secretary-General Ban Ki-moon said Tuesday.