The tsunami threat around Pacific countries was abating on Sunday but the extent of damage remained unknown in Tonga, where a huge underwater volcano erupted the previous day and triggered tsunamis that flooded Pacific coastlines from Japan to the United States, prompting hundreds of thousands of people to evacuate.

The capital of Tonga, Nuku'alofa suffered "significant" damage, New Zealand Prime Minister Jacinda Ardern said on Sunday, adding there had been no reports of injury or death but that a full assessment was not yet possible with communication lines down.

Ardern cited a damaged undersea cable as one reason for difficulties in communicating with Tonga. "The tsunami has had a significant impact on the foreshore on the northern side of Nuku'alofa, with boats and large boulders washed ashore," Ardern said after communicating with the New Zealand embassy in Tonga.

"Nuku'alofa is covered in a thick film of volcanic dust but otherwise conditions are calm and stable."

The volcano, about 65 kilometers north of Nuku'alofa, erupted on Saturday afternoon. Tonga Geological Services said plumes reached more than 19.3 kilometers above sea level, with satellite images showing the huge plume of ash, steam and gas the eruption caused.

As a result, tsunami warnings were in force for all Pacific countries after the eruption.

The Pacific Tsunami Warning Center in Hawaii said tsunamis of up to about 80 centimeters high were observed in Tonga.

High waves triggered

The eruption triggered tsunamis reached about 1.4 meters in Vanuatu, about 3 meters in Japan, over one-meter high in Alaska and California and even 80 centimeters high on the coast of Peru, about 10,000 kilometers from Tonga.

Footage from local TV showed seawater gushing into a coastal town in Peru, where the water rose above knee level, and some people were clinging to pillars to stop themselves from being swept away.

Japan's weather agency issued tsunami warnings from the northernmost island of Hokkaido to Okinawa in the south, and about 230,000 people were asked to leave coastal areas, the country's Fire and Disaster Management Agency said.

Trains, aircraft and postal services were disrupted in the country, with Japan Airlines canceling about 27 domestic flights due to the tsunami.

However, during a news conference on Sunday evening, Japan's Meteorological Agency lifted all tsunami warnings and advisories, saying there may be some tidal fluctuation, but ruled out the possibility of a tsunami.

On Saturday the United Nations Secretary-General Antonio Guterres expressed his deep concern over Tonga and other countries such as Australia, New Zealand, Japan and the United States.

"The United Nations offices in the Pacific are closely monitoring the situation and are on standby to provide support if requested," Farhan Haq, deputy spokesman for the secretary-general, said.

"The secretary-general is grateful to countries that have already offered their support."

Agencies contributed to this story.