US President Donald Trump has taken to Twitter to lash out at the mayor of Puerto Rico's capital city and other officials, contemptuous of their claims of a slow response to the natural disaster that has imperilled the island's future.
Mr Trump sent out a series of tweets criticising San Juan mayor Carmen Yulin Cruz for criticising his administration's hurricane response.
The mayor has accused his administration of "killing us with the inefficiency", and implored Mr Trump to "make sure somebody is in charge that is up to the task of saving lives".
The US leader has pledged to spare no effort to help Puerto Rico recover from Maria's ruinous aftermath, and is set to visit the island early next week.
He responded to the mayor's criticisms by citing her "poor leadership ability", and also took aim at other officials in the US territory who he said had not been able to "get their workers to help".
The US leader said military responders working on the island deserved praise due to the extent of the damage in Puerto Rico, and accused US media organisations of criticising the emergency response in order to "get Trump".
His acting homeland security secretary Elaine Duke had earlier surveyed the Puerto Rican landscape by helicopter, and also drove past still-flooded streets, twisted billboards and roofs with gaping holes.
Meanwhile water and food rations are improving, and telecommunications have been restored to about 30 per cent of the island.
Nearly half of the supermarkets have reopened, at least for reduced hours, and about 60 per cent of the petrol stations are pumping.