TOKYO (Reuters) - A debate over flying saucers has kept Japanese politicians occupied for much of this week, ensnaring top officials and drawing a promise from the defense minister to send out the army if Godzilla goes on a rampage.

"There are debates over what makes UFOs fly, but it would be difficult to say it's an encroachment of air space," Defense Minister Shigeru Ishiba told a news conference Thursday.

"If Godzilla were to show up, it would be a dispatch for disaster relief."

His remarks came after the top government spokesman was asked Tuesday about an opposition politician's demand that the government confirm the existence of unidentified flying objects.

"Personally, I definitely believe they exist," chief cabinet secretary Nobutaka Machimura said, drawing laughter from reporters.

Prime Minister Yasuo Fukuda took a more guarded stance later in the day, saying he has yet to confirm their existence.

The debate started Tuesday when the cabinet issued a statement in response to the opposition lawmaker's question, saying it could not confirm any cases of UFO sightings.