Miyake Island, which was fully evacuated in September due to the volcanic activity of Mount Oyama, may not be safe enough to return to for another three months to a year, a leading expert said Sunday.

Yoshiaki Ida, head of the government's Coordinating Committee for the Prediction of Volcanic Eruptions, made the comments "as a personal opinion" in speaking at a gathering held to encourage the Miyake islanders, who have entered their third month of evacuation, in Tokyo's Minato Ward.

"If we take an optimistic viewpoint," he said, three months to a year may be sufficient to determine that the volcanic activity on the island has subsided enough to ensure the safety of residents, Ida said.

It was the first time Ida made a public comment regarding any target date for the islanders' return. Some islanders, many of whom have indicated they would like to return to their homes as quickly as possible, let out sighs of disappointment at Ida's words.

"While explosive eruptions (at Mount Oyama) have subsided since September, the mountain is still emitting volcanic gas," Ida explained in a speech.

"The amount of gas being released is very unusual, even on a global basis," he said. "If (the gas levels) drop to about a tenth of what they are now, it may be possible to live regular lives on the island."

At the same time, Ida said that while the coordinating committee would convene later this month to discuss the Miyake issue, the lack of strong evidence made it difficult to formulate any official position on when the islanders might return, he said.

On a more pleasant note, Sunday's gathering, which drew more than 1,000 people, gave the evacuees a chance to be reunited with friends and neighbors for the first time since the all-out evacuation order was issued Sept. 1 after eruptions at the 813-meter peak seemed unlikely to subside anytime soon.

At the start of the event, held at an elementary school, Miyake Mayor Ko Hasegawa said authorities were continuing efforts to return the islanders to their homes as quickly as possible.

"It is going to get colder, so I want all of you to take care of your health," he said.

The islanders were treated to food stalls serving local fare as well as performances of traditional songs and dance.

Dozens of photographs recently taken of the island were also displayed. Yasuko Asanuma, 68, of the island's Kamitsuki district said she was relieved to be able to confirm that her house was still all right.

"These days have been lonely, so it was nice to be able to meet with many of my acquaintances today," she said.