​The mayor of Puerto Rico's capital city has slammed a senior Trump administration official for calling the government's disaster response "a good news story," comments that came amid mounting criticism of the federal reaction to the hurricane.

Trump administration officials have defended the federal effort, with acting Homeland Security Secretary Elaine Duke telling reporters on Thursday that the relief effort "is proceeding very well considering the devastation that took place".

San Juan mayor Carmen Yulin Cruz, speaking on CNN, said the disaster response was far from a "good news story". Credit:CNN

She called the federal response "a good news story in terms of our ability to reach people and the limited number of deaths that have taken place in such a devastating hurricane."

After watching Duke's comments, San Juan Mayor Carmen Yulín Cruz appeared visibly taken aback during an interview on CNN, calling the remarks "irresponsible" and saying they upset her.