New Zealand Prime Minister John Key said on Saturday that his country will send a rescue team to Japan. The six-member advanced team will leave for Japan on Saturday night.

The balance of a 48-member rescue team would probably leave on Sunday, following a request from Japan, Key said.

Up to 20 New Zealanders are thought to be unaccounted for in quake-stricken areas of Japan, said the New Zealand embassy to Japan.

Key said he has watched with horror at the scenes of devastation in the wake of the earthquake and tsunami that has struck Japan in the past few hours.

"Our hearts go out to the Japanese government and its people. Japan responded to New Zealand's own tragic earthquake with enormous support, and we are ready to help our friends in Japan at this time of need in whatever way we can," he said.

"Our deepest sympathies are with those who have been caught up in this most terrible event," he added.

New Zealand Foreign Minister Murray McCully has expressed deep concern and sympathy to the people of Japan following a great earthquake hit off the northeast coast of Japan.

"All New Zealanders are concerned to learn of this major quake which has caused extensive damage. Our thoughts are with the people of Japan at this moment as they endeavor to respond to this disaster," McCully said in a statement.