Residents in storm wrecked areas of Micronesia appealed for help Thursday as a clean up began on the worst affected islands after Super Typhoon Maysak swept through the region on its way towards the Philippines.

"We can do with all the help we can get," Courtney Stinnett at the Truk Stop Hotel dive shop on the main island of Weno in Chuuk state told AFP.

A state of emergency has been declared in Chuuk, the largest region in the Federated States of Micronesia (FSM) where five people were killed and houses and crops destroyed by Maysak.

The super typhoon took three days to cross the central Pacific archipelago before heading out to sea and towards the Philippines, but relief workers said it could be a year before some land was restored enough to plant crops again.

"The storm ripped the iron roofs off houses. About 95 percent of the homes were damaged," Stinnett said, adding that residents were gathering scattered sheets of iron to hastily make their wrecked homes rainproof.

"There are fallen trees and you can't get through many back roads," she said.

"There are two live aboards (vessels) which have significant damage after being swept on to the reef. The crew had to jump off and swim to land. Quite a few were injured but all survived."

The Pacific Maritime Association (PMA) sent an aircraft to survey the damage on Ulithi atoll which was hit hard when the eye of the storm passed over on Tuesday night with sustained winds of 260 kilometres per hour (160 mph).

Most concrete structures withstood the fury but everything else was damaged, PMA Pacific administrator Melinda Espinosa said in an email.

"Because Ulithi is just a little above sea level, in some areas the sea rose, destroying crops and the soil. It will take time to desalinate the soil -- approximately a year until the crops can be re-planted," she said.

In Chuuk, Stinnett said they were reliant on ships to bring in relief supplies but they may first be diverted to the many small islands where residents lost their boats and had no way of going for help.

- 'Don't take this lightly' -

On neighbouring Guam, the Bank of Guam and the Ayuda Foundation have teamed up to prepare medical packages which will either be air dropped or delivered by boat to the worst hit islands.

"We are saddened to learn of the deaths and devastation to our neighbouring islands and send our support for a speedy recovery," Bank of Guam President Lou Leon Guerrero said.

The Guam weather office said the maximum sustained winds of Maysak had decreased to 225 kilometres per hour (140 mph) by Thursday and it would continue to weaken before hitting the Philippines at the weekend.

The typhoon is expected to make landfall in the northern Philippines late Saturday or early Sunday as millions of people enjoy the Easter weekend holiday.

Philippines government weather station division chief Esperanza Cayanan said relief goods had been "pre-positioned" and communities in the firing line had been put on alert.

She added that authorities would likely ban ships from leaving port from late Thursday, a move expected to strand thousands of people already lining to take ferries.

"Don't take this lightly. It is fun in the Philippines but it is better to be careful," she warned, adding that coastal areas could be hit by tsunami-like storm surges up to three metres (10 feet) high.

Such storm surges were responsible for many of the deaths when Super Typhoon Haiyan hit the country in November 2013, leaving more than 7,350 dead or missing.