PUERTO RICO announced water rationing measures on Thursday as a drought grips the United States territory, worsening chronic water shortages that have forced the governor to declare a state of emergency.

Friday will see a 48-hour rationing period put in place in the island’s north-east region, said Luis Gonzalez, executive president of the island’s water and sewer authority.

“There’s just not enough water,” he said, adding that rationing will likely be extended to other areas.

Mr Gonzalez blamed a lack of rain, although severe water shortages began affecting some of the island’s most populated areas months before the drought began, with officials yet to identify the problem.

Those outages prompted the mayor of San Juan to sue the island’s water and sewer authority in late May, with Governor Jenniffer Gonzalez acknowledging that the agency’s infrastructure has lacked investment and maintenance for decades.

Almost 40,000 customers were left without water last month.

The US Drought Monitor says 14 per cent of Puerto Rico is currently under a severe drought and another 59 per cent under a moderate drought.

Around 2.3 million people out of Puerto Rico’s 3.2 million inhabitants are currently living in a region affected by drought, it estimates.