A boy missing in remote woods in Japan since Saturday after being left alone by his parents as a punishment has been found alive and well.

Seven-year-old Yamato Tanooka was found in military barracks near Shikabe in northern Hokkaido, just a few kilometres from where he was left.

His parents initially said he had got lost, but eventually admitted briefly abandoning him for being naughty.

His father has apologised to his son and rescuers, saying "we went too far".

"My excessive act forced my son to have a painful time," Takayuki Tanooka said in an emotional news briefing outside Hakodate hospital, where his son was taken for checks.

"I deeply apologise to people at his school, people in the rescue operation, and everybody for causing them trouble," he said.

He also thanked the search teams, and said he had raised his son "full of love until now and I will continue to do so".

Search teams including the Self-Defence Forces (SDF) have been combing the remote area, home to brown bears, for a week.

They had found no trace of Yamato and hopes were fading.

But shortly before 08:00 on Friday morning (23:00 GMT on Thursday) he was found inside a building at the SDF base about 4km (2.5 miles) from where he was left.

"One of our soldiers was preparing for drills this morning and opened the door of a building on the base, and there he was," an SDF member told NHK.

"When he asked 'are you Yamato?' the boy said yes. Then he said he was hungry, so the soldier gave him some water, bread and rice balls."

NHK said he had told rescuers he "walked through the mountains" until he found the shelter.

He was taken to hospital by a medical helicopter.

The Kyodo news agency said he was slightly dehydrated with minor scratches, but otherwise in good health.

Yamato's parents initially said he got lost while foraging for vegetables. But they later admitted they had driven off, briefly leaving him alone on a mountain road as a punishment for throwing stones earlier. When they returned to collect him shortly afterwards, he had disappeared, they said.

He was not thought to have any food or water with him and was wearing only daytime clothing.

Earlier this week, Yamato's father had apologised in the media "for causing trouble for many people".

Police have said the parents could face charges for negligence.