SEOUL - A senior military official in South Korea has clarified that mega boy band BTS can postpone their mandatory military service because it is in the country's "national interest".

Under a recent amendment to the country's Military Service Act, the chart-topping septet can defer their military service until the age of 30.

Head of Seoul's Military Manpower Administration Jung Seok-hwan told South Korean newspaper Kyunghyang Shinmun that exceptions were made for "outstanding artists" who "increase the value of the national brand".

He was speaking on the military's official position after an amendment to the Military Service Act went into effect June 23.

The amendment allows South Korean men to defer their military service until the age of 30 if they have received cultural merit awards from the Ministry of Culture, Sports, and Tourism.

By law, South Korean men are required to enlist by 28.

This means that the oldest member of the group, Jin, 28, can now wait till 2022 to enlist. Jungkook, the youngest at 23, can defer military service until 2027.

The boy band were conferred the Order of Cultural Merit in 2018 for their contributions to the global popularity of Korean culture and encouraging more people around the world to learn the Korean language.

This honour is usually given to those with more than 15 years of contributions, but BTS were given the award five years after their debut.