1. President Trump is with world leaders in Buenos Aires for a two-day meeting of the Group of 20 industrialized countries. Above, the president with Prime Minister Shinzo Abe of Japan and Prime Minister Narendra Modi of India.

At the top of Mr. Trump’s agenda: signing a new North American trade pact this morning with the leaders of Canada and Mexico, after 14 months of acrimonious negotiations. The president called it a victory, but back in Washington, newly empowered House Democrats — along with business leaders and free-trade Republicans — say the new deal faces long odds in Congress without significant changes.

Mr. Trump is scheduled to have dinner with President Xi Jinping of China on Saturday. Tensions over the trade war have made this a particularly fraught time, our reporters say as they assess whether the two nations are destined to enter a new era of Cold War-like confrontation.