North Korea is still using a uranium-enrichment facility at the heart of last week’s summit between President Trump and North Korean leader Kim Jong Un, the United Nations atomic agency said.

BEIJING—China accused two detained Canadians of working together to steal Chinese state secrets, moving ahead with a politically charged investigation seen as retribution for Canada’s arrest of a senior Huawei Technologies Co. executive.

SEOUL—Troubled by the failure of the U.S. and North Korea to reach a deal on sanctions relief in exchange for Pyongyang’s disarmament, South Korea is pressing the two sides to return to negotiations to prevent the diplomatic detente from unraveling.

BOGOTÁ, Colombia—Venezuelan opposition leader Juan Guaidó said he plans to return home on Monday in a high-stakes strategy that directly challenges President Nicolás Maduro’s authority and could end with Mr. Guaidó in jail.

CASAMICCIOLA TERME, Italy—Angelo Croce was playing in a table-soccer tournament in this village on the island of Ischia when the ground began to shake violently. He ran home in a panic.

BEIJING—President Xi Jinping, battling a persistent downturn in China’s economy, is trying to gird his rule by demanding absolute loyalty from the Communist Party in an effort to stifle simmering dissent.