SAN JUAN, Puerto Rico - Hurricane Maria, an "extremely dangerous" storm, made landfall on the small island of Dominica Monday night as a Category 5 storm, then weakened ever-so-slightly, the U.S. National Hurricane Center (NHC) said early Tuesday.

Maria was pummeling  Dominica with maximum sustained winds of 155 mph as it surged into the eastern Caribbean, and forecasters warned it might become even stronger.

A series of Facebook posts by Dominica Prime Minister Roosevelt Skerrit captured the fury of the storm as it made landfall on the mountainous island.

"The winds are merciless! We shall survive by the grace of God," Skerrit wrote at the start of a series of increasingly harrowing posts.

A few minutes later, he messaged he could hear the sound of galvanized steel roofs tearing off houses on the small rugged island.

He then wrote that he thought his home had been damaged. And three words: "Rough! Rough! Rough!"

A half hour later, he said: "My roof is gone. I am at the complete mercy of the hurricane. House is flooding." Seven minutes later he posted that he had been rescued.

It was the first official word from Dominica after the eye wall moved ashore.

The storm was on a path that would take it near many of the islands already wrecked by Hurricane Irma and then on toward Puerto Rico and the Dominican Republic. Maria could hit Puerto Rico on Wednesday, said Ernesto Morales with the U.S. National Weather Service in San Juan.

"This storm promises to be catastrophic for our island," he said. "All of Puerto Rico will experience hurricane force winds."

The NHC's 2 a.m. advisory said Maria's eye was some 45 miles west-northwest of Dominica and was moving west-northwest at  9 mph.

The NHC forecast Maria's eye would move over the northeastern Caribbean Sea on Tuesday and approach the Virgin Islands and Puerto Rico Tuesday night and Wednesday.  

Hurricane warnings were issued for Puerto Rico, Culebra, Vieques, the U.S. and British Virgin Islands, Guadeloupe, Dominica, St. Kitts, Nevis and Montserrat. A tropical storm warning was issued for Antigua and Barbuda, Saba, St. Eustatius, St. Martin, St. Lucia, Martinique and Anguilla.

University of Miami hurricane researcher Brian McNoldy says one key sign of Maria's growing strength is what center forecasters call "the dreaded pinhole eye." Maria's eye has shrunk to 10 miles in diameter -- a smaller, tighter eye makes the hurricane spin faster.

McNoldy says meteorologists saw a similar pinhole eye when Hurricane Wilma set a record for lowest central pressure -- a key measure of storm power -- in 2005.

President Trump approved an emergency declaration for the U.S. Virgin Islands ahead of Maria, ordering federal assistance to aid the response effort, the White House said in a statement Monday. The action authorizes the Federal Emergency Management Agency (FEMA) to coordinate disaster relief efforts. 

"FEMA is authorized to identify, mobilize, and provide, at its discretion, equipment and resources necessary to alleviate the impacts of the emergency," the statement said.

The Associated Press contributed to this report.