After months of efforts to restore power to hurricane-hit Puerto Rico, electricity provider AEE said on Friday that 55 percent of households now had electricity.

That means that some 660,000 customers out of a total 1.5 million are still without power, AEE director Justo Gonzalez said. It was the government-owned utility's first statement since Hurricane Maria slammed into the US territory on September 20.

Read more: Trump's request for $44 billion in hurricane aid slammed as 'woefully inadequate"

The town of Ciales, one of the island's 78 municipalities, is still totally without electricity. No towns in Puerto Rico have had their power networks completely restored, Gonzalez said.

AEE said that it had given priority to restoring power to shopping centers, hospitals and factories.

Puerto Rico's government also cautioned that a lot of work remained as crews were still uncovering unexpected damage after the Category 4 storm hit in September, blowing down power lines and crippling substations with winds of up to 154 mph (248 kmh).

The island's governor, Ricardo Rossello, appealed to US utility companies on Friday to send 1,500 workers to Puerto Rico to speed up electricity recovery efforts.

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Frustration from Puerto Ricans

People around the island were surprised and frustrated by the statistics released by officials on Friday.

"This is horrible," Amarilis Irizarry, a 38-year-old graphic designer living in Trujillo, told The Associated Press. "I didn't think it would take so long ...To have only half of Puerto Rico with power three months after the hurricane, that's worrisome," she said.

San Juan Mayor Carmen Yulin Cruz said in an interview earlier this week that Washington's response to the storm was inadequate and that US President Donald Trump was the "disaster-in-chief."

"He was disrespectful to the Puerto Rican people; he was disrespectful to the American people who were leaving their homes to come help us here," she told ABC News.

The US Army Corps of Engineers has estimated that power will likely be completely restored to the island by May.

rs/tj   (AP, dpa)