Previous summits have ended with funds established to help developing countries transition to green energies, pledges to slash pollution and promises to keep people most vulnerable at the centre of policy discussions.
President Donald Trump's decision to withdraw from the Paris Agreement is a heavy blow to a deal that in many ways was designed to ensure the participation of the United States.
Opposition parties and international legal experts are calling on Ottawa to say what it plans to do about three UN drug treaties that pose a conundrum for the Liberal government plans to legalize pot.