Canada is rolling out the red carpet for some of the world’s biggest powers and their allies amid a perilous escalation in the Middle East and President Trump’s reshaping of global alliances.

The annual meeting of the Group of 7 nations — Britain, Canada, France, Germany, Italy, Japan and the United States — is an important forum where the United States and many of its traditional partners have in the past met to find common ground on critical issues. It begins on Sunday in Kananaskis, a stunning resort in the Canadian Rocky Mountains in Alberta, and will run until late Tuesday.

While the agenda includes wildfires, the global economy and Ukraine, most leaders will attend with one goal in mind: to meet Mr. Trump and, if they do, to avoid any unpleasantries.

Some past summits have offered little more than polite handshakes and a cheerful group photo. Others have seen unscripted high drama.

The 2018 gathering, also held in Canada, was memorable for the spectacular fallout between Mr. Trump and Justin Trudeau, who was then Canadian prime minister. It also produced an iconic photo of the German chancellor at the time, Angela Merkel, leaning over Mr. Trump as they disagreed over allowing Russia to attend the group’s meetings. The image captured the world leaders’ concern over Mr. Trump.

Who’s going?

The G7 summit is attended by leaders from the seven member countries and the European Union, but leaders of other important global allies are also invited. This year attendance will be unusually high. Prime Minister Mark Carney of Canada, who this year holds the G7 presidency, has invited the leaders of several nonmember countries: India, Brazil, South Africa, Mexico, Ukraine, Australia and South Korea, and the head of NATO.