A tsunami has been generated in the Pacific Ocean after a powerful earthquake between the island nations of Samoa and American Samoa, officials have said. 

In Apia, the Samoan capital, local media reported that people had fled their homes for higher ground after a tsunami warning was issued on Tuesday.

Waves of 1.57 metres higher than normal sea level hit Pago Pago, the capital of American Samoa, the West Coast/Alaska Tsunami Warning Centre said.

While in Western Samoa some residents told Radio New Zealand that they had also been encouraged to move to higher ground after the quake had caused a huge jolt.

The US Geological Survey said the epicentre of the 8.3 magnitude temblor was 204km southwest of Apia at a depth of 85km.

A tsunami warning was issued for Niue Island, the Wallis and Futuna Islands, the Tokelau atolls, the Cook Islands, Tuvalu, Kiribati, the Kermadec Islands, the Baker and Howland Islands, Jarvis Island, French Polynesia, the Palmyra Islands as well as Samoa and American Samoa.

"An earthquake of this size has the potential to generate a destructive tsunami that can strike coastlines near the epicenter within minutes and more distant coastlines within hours," a statement from the Pacific Tsunami Warning Centre said.

"Authorities should take appropriate action in response to this possibility," the statement said.

However, there was no immediate word of any casualties or damage from the quake or the tsunami.

Keni Lesa, a resident of Apia, told the AFP news agency: "I'm taking my family to a safe place. Everyone's getting out of coastal areas."

But he said that there was no panic as "we have done a lot of training for this".