Ts.Elbegdorj, President of Mongolia, officially delivered the country’s ratification of the Paris Agreement to Mr Ban Ki-moon, the Secretary-General of the United Nations. As of Wednesday (21^st of September), thirty-one countries had formally joined the Paris climate change pact bringing the total number of countries to ratify the treaty to 60.

"I am convinced that the Paris Agreement will enter into force before the end of 2016," Secretary-General Ban Ki-moon said at an event on the sidelines of the high-level U.N. General Assembly gathering.

The world's two biggest emitters, the United States and China, have already ratified the deal. Brazil, Mexico and Argentina were the largest emitters to join the treaty on Wednesday.

The international deal to attempt to limit the rise in global temperatures to less than 2C was agreed at the climate change summit in Paris in November.