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.

Leaders of some of the world’s biggest economic powers arrive in the Canadian Rockies on Sunday for a Group of Seven summit, overshadowed by an escalating conflict between Israel and Iran and U.S. President Donald Trump’s unresolved trade war with allies and rivals alike.