Canada's environment minister says it's time to accept the U.S.'s departure from the Paris climate change accord and move forward with getting a strong statement from the remaining 19 countries in the G20.

"There's going to have to be some recognition that the U.S. is not part of the Paris agreement, that's just a fact," Minister of Environment and Climate Change Catherine McKenna told CBC Radio's The House.

McKenna said that while the U.S. has left the climate change table she would consider it a success if she could get "recognition of the Paris agreement, and the importance of climate action, by maybe 19 out of 20 countries," in Hamburg

Trump's decision to leave the Paris agreement, a deal he called "very unfair to the United States," puts him at odds with the G20's host leader, German Chancellor Angela Merkel.

She has put forward an appendix to the official G20 communiqué, the document the leaders will sign declaring what was decided in the meeting, around climate and energy.

The working draft of Merkel's plan includes language on everything from sustainable infrastructure to energy efficiency.

Minister of Environment and Climate Change Catherine McKenna says Canada can bridge the gap between the U.S. and the rest of the G20. (Adrian Wyld/Canadian Press)

Prime Minister Justin Trudeau and Merkel discussed strategies to get as many other leaders as possible on board during their one-on-one meeting in Hamburg on Friday.

"The prime minister has a unique role — he's been strong on climate action and the Paris agreement, but also we have a relationship with the United States, and we want to try and bring them into this conversation too," said McKenna.

"These conversations are very difficult, it's a negotiation. These things are hard," she said.

Céline Bak, a climate policy and G20 expert who is a senior fellow at the Centre for International Governance Innovation, said the best case would be for Trump to at least sign on to Merkel's climate appendix.

"Perhaps that's not in the cards, and in which case the agreement of 19 of the world's global leaders to that action plan would, I think, be a very important accomplishment," she said.

Even without Trump's signature, Bak said, some individual states, cities and corporations are keen to echo the principles of the Paris agreement.

"We can't wait for another presidency to really move forward with commitments that have been made in Paris and to actually achieving those," she said.