Leaders of some of the world’s biggest economic powers will arrive in the Canadian Rockies on Sunday for a Group of Seven summit overshadowed by a widening war across the Middle East and U.S. President Donald Trump’s unresolved trade war with allies and rivals alike.

Prime Minister Mark Carney will welcome leaders of the world's most powerful democratic countries Sunday for the start of a three-day meeting in the Rocky Mountains — a high-stakes summit that longtime G7 observers say could be one of the most consequential in years.