Despite the seriousness of the matter, Prime Minister Justin Trudeau and U.S. President Donald Trump were all smiles ahead of their bilateral meeting at the G7 summit.

The future of military alliances, the fight against climate change and even free trade are all expected to be on the agenda as Trump sits down with his NATO and G7 counterparts.

Justin Trudeau heads to Europe this week for the NATO and G7 summits, where global leaders are trying to figure out exactly how the world works now that U.S. President Donald Trump is at the table.