"The Chinese people honor their commitments. We will work hard to earnestly implement the Paris Agreement," Zhang said.

"We will launch a national emission trade market, substantially increase forest carbon sink. We will put in place a strict accountability system for environmental protection and ensure the implementation of all targets," he said.

The Chinese special envoy also stressed the importance of international cooperation on the fight against climate change.

"China will take an active part in the follow-up negotiations of the Paris Agreement. We will deepen South-South cooperation on climate change," he added.

After the opening ceremony, national leaders are being called to the podium in the UN General Assembly Hall to sign the agreement one by one.

Taking place on the International Mother Earth Day, the signing ceremony would break the first-day record for signatures which was set in 1982 when 119 states signed the UN Convention on the Law of the Sea.

After the signing, national representatives will have the chance to speak throughout the day and a high-level event on implementation will be convened in the afternoon.