SEOUL: South Korea's government is asking Samsung Electronics to extend the refund period for its Galaxy Note 7 smartphones that have been subject to an unprecedented recall.

Nam Taek-joo, an official at the Korean Agency for Technology and Standards, said Thursday that the agency has not approved Samsung's smartphone recall plan because its measures on how to remove the Note 7 already in the market were inadequate.

The agency asked Samsung earlier this week to say how long it could extend the refund period for consumers who missed Monday's deadline.

The phone went on sale in South Korea on August 19 but sales stopped September 2, with Samsung citing a battery manufacturing error that caused the lithium battery to overheat or catch fire.