In early August, China’s foreign minister said the country had stopped land reclamation projects in the South China Sea that were worrying neighbors and irking the U.S. With Chinese President Xi Jinping gearing up for a state visit to the U.S., a Washington-based think tank has published satellite images that cast doubt on that statement.

A report published earlier this week by the Center for Strategic and International Studies contains high-definition photos of Chinese-controlled reefs in the disputed Spratly Islands taken...