"We have supported China all the way as it prepares to launch the world's biggest emissions trading scheme. And our clean energy partnership will ensure that the energy transition is here to stay," Juncker said in an interview ahead of the Chinese-EU summit held on Thursday and Friday.
Earlier on Thursday, media reported, citing Miguel Arias Canete, EU Commissioner for Climate Action and Energy, that the sides planned to reveal at the summit their joint declaration, calling on all the Paris climate deal parties to uphold the agreement as well as to show the "highest political commitment" to doing so themselves.
Apart from this, according to other reports earlier in the day, China's Premier Li Keqiang said that Beijing "in recent years has stayed true to its commitment" on the Paris agreement.
US President Donald Trump, who has repeatedly expressed readiness to withdraw from the deal during his presidential election campaign, wrote on Twitter that he would announce his decision on participation in the international agreement, at 3 p.m. local time (19:00 GMT) on Thursday.
The Paris climate deal, created within the UN Framework Convention on Climate Change and championed by former US President Barack Obama, was signed in 2015 by 194 countries and ratified by 143. The agreement aims at keeping the increase in average global temperature at below 2 degrees Celsius above pre-industrial levels, by reducing greenhouse gas emissions. To this end, all the signatory states agreed to reduce or limit their greenhouse gas emissions.