The president’s comments come at a crucial moment in talks among the three countries over the renewal of their free-trade agreement.

© Kenny Holston/The New York Times

Cars and a bus were set on fire and families were driven from their homes after a stabbing caused tensions to spill onto the streets.

© Peter Morrison/Associated Press

The death of the officer appeared to add to a string of targeted assassinations of high-profile opponents of Ukraine inside Russia.

© Yulia Morozova/Reuters

The president’s top advisers gathered in a series of Situation Room meetings as they struggled to contain a scandal engulfing Donald Trump himself.