The European Union has indicated it will work closely with China to prevent the US from backsliding on its commitment to the Paris climate agreement.

The message was delivered by a 12-strong European Parliament delegation before it left for Marrakech, Morocco, for the second week of the UN climate change conference.

Parties that have approved the global pact will start their first talks at the conference, and President Xi Jinping and United States President Barack Obama have signed three presidential documents to inject special political will into the approval process.