The Puerto Rico Electric Power Authority (PREPA) announced Friday it failed to meet Gov. Ricardo Rossello's goal of restoring power to 80 percent of the island's 3.4 million residents.

PREPA acting Director Justo Gonzalez cited "natural" and hurricane damage to the power grid that was initially unidentified as the reason for the delay of power generation, and only 66 percent of residents have electricity now, according to a government-run website detailing utility coverage.

"These are fortuitous causes, over which we have no control," Gonzalez told El Nuevo Día. "We had to fight against nature. Rain and fog made it difficult for the staff to work in the towers. The conditions in which the staff had to work were very difficult."

Rossello in October also said he expected 95 percent of the island's power to be restored by Dec. 15. Others have said full power and other utilities will not be completely restored until March.

"The governor set some challenging goals ... to give importance and priority to the energization of Puerto Rico. They will be reached, but I do not want to give a date. What I do want to mention is that the goal is to completely energize Puerto Rico," Gonzalez added.

Power has slowly come back on throughout the island since the September storm destroyed most of the U.S. territory.

Category 4 Hurricane Irma swept over the island on Sept. 20 and left 1.1 million customers without power. As of late September, only one-in-six residents had had power restored.

Rossello announced in November the storm left behind $94 billion in damages to the 100-mile wide island.