The National Hurricane Center said Marco's sustained winds had decreased to 70 miles per hour (110 kph), though it still warned of life-threatening storm surges and dangerous along the U.S. Gulf Coast.

On Thursday while still a tropical storm, Isaias knocked out power, toppled trees and caused widespread flooding and small landslides in the Dominican Republic and Puerto Rico.

The U.S. National Hurricane Center said the storm was expected to move over or near Puerto Rico on Wednesday night before possibly hitting the U.S. mainland by the weekend.

Not a single repair or rebuilding job has been completed under a government program meant to repair and rebuild damaged homes.

The quake hit at a shallow depth of four kilometres near the city of Ponce and the towns of Guanica and Guayanilla, where hundreds of homes were destroyed by a quake in early January.

Puerto Rico's governor said she had ordered an investigation after learning the emergency supplies had been piled in the warehouse since Hurricane Maria battered Puerto Rico in September 2017.

Last year, U.S. President Donald Trump threatened to divert disaster-recovery funds from Puerto Rico to help pay for a wall at the U.S.-Mexico border.

A magnitude 6.0 quake shook Puerto Rico on Saturday, causing further damage along the island's southern coast, where previous recent quakes have toppled homes and schools.

The country has been experiencing earthquakes on and off since Dec. 28.

A 6.4-magnitude earthquake struck Puerto Rico before dawn on Tuesday, the largest in a series of quakes that have struck the U.S. territory in recent days and caused heavy damage in some areas.