"We'll demonstrate that we are serious about climate change," Trudeau said following a four-hour working dinner with provincial and territorial leaders.
First minister's meeting is not expected to produce any new national target for reducing emissions - but will set a fresh tone for Canada one week before Paris.
Does Trudeau need to atone for all Stephen Harper's 'climate fossil' awards? Or merely craft a coherent policy that will put Canada - and the world - on track towards a low-carbon future?
$4.3-billion compensation package the previous Conservative government made to dairy farmers to counter any ill effects of the Trans-Pacific Partnership is not a done deal.
Trudeau will hold a key bilateral meeting with U.S. President Barack Obama at the Asia-Pacific Economic Co-operation Summit - with refugees and climate change top priorities.
Liberal plan to bring in 25,000 Syrian refugees by year-end — even amid heightened security concerns around the world — has made several provinces nervous about security
PM reaffirmed Canada's commitment to accept 25,000 Syrian asylum seekers and stressed that Canada is a country that defined by shared values - not cultural differences.
Friday's co-ordinated strikes in the French capital, which left at least 129 dead and many more wounded, threatened to overshadow the G20's economic agenda.
Key planks of Trudeau's platform — from spurring economic growth through deficit-financed infrastructure, to tackling climate change, to helping refugees — fit well with G20 agenda.
Canada's new government must tread carefully and lay proper groundwork for an inquiry into missing and murdered aboriginal women, says a coalition of First Nations and advocacy groups.