In Mexico, Adams Praised Migrants. He Also Told Them to Stop Coming.

Mayor Eric Adams of New York City touched down in Mexico this week on an urgent four-day mission: to witness firsthand the forces that have brought more than 120,000 migrants to New York, and to warn migrants in transit of the misery that awaits them once they arrive.

He planned to visit the passageways migrants take through Ecuador and Colombia — including a treacherous stretch of jungle along the border of Colombia and Panama known as the Darién Gap. But first, Mr. Adams spent 24 hours in Mexico cheerleading for...