Three islands in the U.S. commonwealth _ Saipan, Tinian and Agrihan _ were under a typhoon warning, while a typhoon watch for Rota was downgraded to a tropical storm warning, the National Weather Service said. A tropical storm warning for the neighboring U.S. territory of Guam was canceled.
Most businesses had shut down by Saturday morning, and Saipan residents who don't live in concrete homes have moved to typhoon shelters, said Charles Reyes, Northern Marianas Gov. Benigno Fitial's press secretary.
The storm, with maximum sustained winds of 130 mph, was expected to make its closest approach to Saipan Saturday night, the weather service said.
As of late Saturday morning, Melor was located 140 miles northeast of Saipan, moving to the northwest at 12 mph. Typhoon force winds of at least 74 mph extended up to 70 miles from the center of the storm.
Saipan, Tinian and Agrihan were forecast to take the brunt of the storm, with the National Weather Service saying damaging winds could knock down trees, triggering power outages.
Rainfall of up to 6 inches and waves as high as 16-feet were possible, forecasters said.
Some airlines canceled flights in the Northern Marianas as residents stocked up on emergency supplies as the typhoon headed their way.
The government has opened six shelters on Saipan and one on Tinian. Most government and private sector employees were told to leave work Friday, and many went to board up and stock their homes.
Guam villagers living in tin-and-wood homes had been urged to seek refuge in storm shelters.
Residents have been rescued from collapsing homes during previous typhoons, so they were asked to relocate to shelters ahead of this storm, Yigo Mayor Robert Lizama said. Hundreds have relocated to 12 public schools designated as storm shelters, he said.
The U.S. Coast Guard advised mariners not to leave shore until the storm passes.
Meanwhile, the Federal Emergency Management Agency prepared food, water and beds as Typhoon Melor closed in. The agency had more than 90,000 meals, 2,500 cots, 3,800 blankets and 85 power generators waiting in the Northern Mariana islands and Guam.
An additional 110,000 meals and more supplies are ready to be shipped from Hawaii to wherever they're needed. Those supplies are also available to help the recovery from the tsunami that hit American Samoa earlier this week.
Guam is located about 3,700 miles southwest of Hawaii, just south of the Northern Mariana islands.