The first tsunami from the Chile quake hit Japan's outlying islands on Sunday, but the initial waves were small, though officials warned a bigger surge of water could reach the country's main islands.
Japan's Meteorological Agency said the first tsunami to reach Japan after the magnitude 8.8 quake off Chile was recorded in the Ogasawara islands. It was just 10 centimetres high. There were no reports of damage.
Japan put its entire eastern coastline on tsunami alert Sunday and ordered hundreds of thousands of residents in low-lying areas to seek higher ground as waves generated by an earthquake off Chile raced across the Pacific at hundreds of kilometres per hour.
It was the first such alert for Japan's coasts in almost 20 years.
Towns along northern coasts issued evacuation orders to hundreds of thousands of residents. Japan's national broadcaster NHK switched to emergency mode, broadcasting a map with the areas in most danger and repeatedly urging caution.
The 8.8-magnitude earthquake triggered a tsunami that swept across the Pacific on Sunday, but little damage was being reported as nations evacuated their coastlines well in advance of the waves.
The Pacific Tsunami Warning Center already lifted its warning for every country but Russia and Japan, though some countries in Asia and the Pacific — including the Philippines, Australia and New Zealand — were keeping their own watches in place as a precaution.
As the wave continued its expansion across the ocean, Japan's Meteorological Agency said its tsunami alert applied to its entire Pacific coast, with the waves expected to be biggest in the north.
In Tokyo, Chief Cabinet Secretary Hirofumi Hirano told a news conference the government has set up a crisis control task force to deal with the possible tsunami danger.
"We will do our utmost to minimize the possible tsunami damage," Hirano said.
Towns along northern coasts issued evacuation orders to hundreds of thousands of residents, and authorities urged people close to the shore to head for higher ground.
People packed their families into cars, but there were no reports of panic or traffic jams. Fishermen secured their boats, and police officers patrolled beaches, using sirens and loudspeakers to warn people to leave the area.