A severe supply breakdown has brought new attention to diplomatic contacts between two adversaries. Officials on both sides are using the same moment to press very different demands.

The head of the CIA has visited Cuba as the island struggles with a severe energy crisis - made worse by a US fuel blockade.

Widespread protests broke out across Havana on Wednesday evening as rolling blackouts in parts of the city spanned 24 hours or more, threatening to spoil frozen food reserves and making sleep all but ...