Authorities said the storm on Tuesday killed at least 456 people, injured 445 and left more than 500 missing.
At least 26 municipalities and four provinces had already declared a state of calamity, Ricky Carandang, communications secretary for the National Disaster Risk Reduction and Management Council, told ABS-CBNnews.com.
Aquino visited some of the areas hardest hit by the storm, including Mindanao and New Bataan, which was nearly leveled by the most powerful typhoon to hit the island nation in decades, Voice of America reported.
The Category 5 storm, measuring more than 500 miles in diameter, roared onto densely populated Mindanao island with winds of 110 mph, forcing more than 50,000 people out of their homes and into shelters.
The storm, known locally as "Pablo," sent roofs flying, uprooted acres of coconut trees, and sent rivers and streams bursting over their banks.
Aquino said the government is investigating why an evacuation center and military camp in the gold-mining province of Compostela Valley were situated in flood-prone areas. The centers were washed away during mudslides and flash floods, Voice of America reported.
Environment Secretary Ramon Paje said there are illegal logging "hot spots" all throughout the Compostela Valley because trees are stripped from the area to create support beams for gold-mining tunnels. The lack of trees in the area could be a key factor in landslides and floods, The New York Times reported.
"In these illegally logged areas, what do you expect but landslides?" Sen. Loren Legarda asked.