HAMBURG - Prime Minister Justin Trudeau begins his G-20 meeting in earnest today after basking in the approving glow of a rock concert crowd in Hamburg.

Trudeau, along with his wife Sophie, introduced the band Coldplay and spoke of Canada's feminist international development policy -- a theme he plans to raise with the G-20 leaders this weekend.

The summit gets fully underway today, but the leaders were already meeting each other in bilateral tete-a-tetes last evening.

U-S President Donald Trump sat down with German Chancellor Angela Merkel, with whom he shares a fractious relationship.

For his part, Trudeau will hold bilateral meetings today the German Chancellor Angela Merkel, French President Emmanuel Macron and Indian Prime Minister Narendra Modi.

During the summit, tensions are expected to flare around everything from climate change to free trade deals, but much of the attention is likely to be on a much-anticipated head-to-head between Trump and Russia's Vladimir Putin today.