Apple's Japan unit will replace any iPod nano portable music players that overheat, it said in an online statement, improving an earlier offer to replace only their faulty batteries.
The concession yesterday came after Japan's trade ministry put the world's largest technology company under scrutiny, ordering it to publish an "easy to understand" statement on its website explaining how users of the devices could receive replacement batteries and obtain advice.
The first generation models, sold between September 2005 and December 2006, have been responsible for around 60 incidents of overheating in Japan, including four cases of minor burns, according to the Ministry of Economy, Trade and Industry (METI).
Apple described the incidents as "very rare" and has blamed the problem on a single battery supplier, without identifying the maker.
A spokesman for the US company in Tokyo on Wednesday declined to comment on the number of the devices sold in Japan or on the spat with the Japanese government.
"We've worked closely with METI to make sure first-generation iPod nano customers who are concerned with their battery have the latest information," US-based spokesman Tom Neumayr had said on August 6.
METI said it was "truly regrettable" that it took Apple until Sunday to report around 30 of the incidents of overheating.