Seoul has confirmed their neighbours launched a projectile towards the East Sea in what is believed to be the North’s seventh set this year.
The sixth launch occurred on Thursday last week, while two ballistic missiles were believed to have been fired on January 14 and 17.
However, on January 5 and 11 South Korea announced they believed hypersonic missiles were launched by the North.
South Korea’s Joint Chiefs of Staff on Sunday didn’t immediately reveal whether the weapon was ballistic nor how far it flew.
Sunday’s launch came just three days after Pyongyang fired two short-range ballistic missiles towards the East Sea on Thursday.
North Korea also tested a pair of long-range cruise missiles last Tuesday after promising to strengthen its nuclear “war deterrent”.
North Korea has been ramping up its testing activity in recent months.
The last time North Korea tested this many weapons in a month was in 2019, after high-profile negotiations between leader Kim Jong Un and former US President Donald Trump collapsed.
Earlier this month, North Korea hinted it could resume nuclear and long-range weapons tests, which have been on hold since 2017.