Three men on a fishing boat which had been missing from the Pacific island group of Kiribati since Saturday have been found safe and well.

A New Zealand Air Force Orion found the boat about 3pm today, 12.5 nautical miles east of Tarawa Atoll, NZ Rescue Coordination Centre spokesman Ross Henderson said.

"The Orion began searching about 1pm and just after 3pm they spotted three men waving in a boat on the water," Mr Henderson told NZPA.

"The Orion dropped a pack with maritime radio and some supplies to them. A local police patrol vessel was making its way towards the boat and was expected to arrive about 5.45pm."

The boat's propeller missing or damaged and its motor was up out of the water, indicating engine trouble caused it to break down, Mr Henderson said.

He was unsure what communications the boat had on board.

The Orion flew out of Auckland yesterday to search for the boat, which left Tarawa Atoll about 3am Saturday morning to fish between Tarawa and Maiana atolls.

The boat did not return to Tarawa later that morning as scheduled, prompting a request for help from the Rescue Coordination Centre Fiji for airborne surveillance to assist the local navy patrol vessel in its search.

It was the fourth international callout for the air force in 10 days.

Mr Henderson said the Orion arrived in the Pacific last night via the Marshall Islands, where it needed to stop in order to get sufficient fuel.