The move will ferry hundreds of US Marines to the storm-ravaged country as well as vehicles able to operate in flooded, debris strewn areas, officials said.
The US State Department has meanwhile confirmed two American fatalities from the storm which is feared to have claimed as many as 10,000 lives.
The USS Germantown and USS Ashland, amphibious warfare vessels designed to transport and launch landing craft and vehicles, have been ordered to depart for the Philippines from the southern Japanese port of Sasebo, said a Navy official, who spoke on condition of anonymity.
“The ships will get under way from Sasebo shortly,” the Navy official told AFP.
Another vessel, the USS Denver, an amphibious transport dock ship, had been placed on standby to prepare to deploy as well, officials said.
All three have landing decks that can serve helicopters as well as medical facilities and the capability to produce desalinated water.
The US military often employs its versatile amphibious ships for disaster relief efforts.
General Paul Kennedy, who is leading a contingent of Marines that has arrived in the Philippines, requested the amphibious ships, a senior Marine Corps official told reporters.
The general has also asked for Osprey tilt-rotor aircraft, which can land like a helicopter and fly like an airplane, and amphibious assault vehicles that could be used where roads are blocked by debris, said the official, who asked not to be named.
“We’re not ruling in or out any capability that may be required to support our Philippine allies as they sort out this very terrible situation,” Pentagon spokesman George Little told a news conference, saying no final order has been issued for more ships.
The American military has a team of 243 Marines on the ground in hard-hit Tacloban on Leyte island to carry out an initial assessment of humanitarian needs.
The US military presence “will be growing every day,” said the Marine Corps official, adding that it will likely expand to about 1,500 to 2,000 troops in coming days.
Washington had already ordered urgent emergency efforts in response to the massive typhoon, which has destroyed entire coastal communities.
On Monday evening, the Pentagon announced it was dispatching the aircraft carrier George Washington and its accompanying cruisers and destroyers, including its fleet of 11 helicopters and dozens of airplanes.
The carrier group is due to arrive on Thursday or Friday.
Another naval destroyer and a supply ship are also en route to the Philippines.
As of Monday, US Osprey and KC-130 aircraft had delivered 107,000 pounds (48 metric tonnes) of food, water and other emergency supplies to the Philippines government, officials said.
The Marines can draw on tap water units, transport trucks and Humvee vehicles pre-positioned in the capital Manila, officials said.
American forces also had evacuated more than 160 refugees from the Tacloban area.
The US Agency for International Development also is sending enough emergency shelter and basic hygiene supplies to assist 10,000 families in the Philippines, Little said. — Agence France-Presse