He told journalists Tuesday (18 November) that he wanted to meet the top EU environment officials “before we all go to Lima”.

Climate negotiators will meet in the Peruvian capital next month to discuss an international agreement, which is meant to be adopted in Paris at the end of 2015.

Stern praised the EU for its target – agreed in October - of reducing greenhouse gas emissions by 40 percent by 2030.

“I have full on admiration for the EU on climate change”, he said.

“I absolutely recognise the EU as a world leader in climate change. The EU has been that for a long time, certainly since I have been in this job.” The EU was the first to make public its commitments for the post 2020 period.

Stern’s word come after US President Barack Obama and his Chinese counterpart Xi Jinping in a surprise move last week announced emission-reduction targets - well ahead of the 31 March, 2015 deadline.

Obama said the US will reduce its greenhouse gas emissions by between 26 and 28 percent in 2025. However, the US uses a different baseline – the year 2005 - to the EU – the year 1990.

This has caused some to say that Washington’s pledge is not ambitious enough.

Nevertheless, Stern said the US target is “roughly comparable to the EU's newly announced target reductions”.

Stern also discussed the $3 billion US contribution to the UN Green Climate Fund, which has been set up to support developing nations cope with the effects of climate change and help them reduce emissions.

Obama's pledge however depends on whether the US Congress is willing to approve it. Republicans, who now control both houses in Congress, have criticised both the financial pledge and the climate deal with China.

“We can take a lot of action without Congress in terms of mitigation. When it comes to finance, we will need congressional support”, said Stern.

Overall he noted that there is “some good momentum” to reach an international climate deal in Paris in 2015.