South Korea's presidential office says it's closely looking into the situation surrounding North Korea’s firing of another projectile following the regime's previous launches last weekend. 

Presidential spokeswoman Ko Min-jung said on Thursday that Director of National Security Chung Eui-yong has been closely monitoring the situation through video conference communications with the Defense Ministry and the Joint Chiefs of Staff(JCS). 

The top office said details of the latest launch remain unconfirmed, adding it will decide later whether to convene a National Security Council(NSC) meeting. 

A NSC meeting usually takes place every Thursday. This week’s meeting was known to have occurred earlier. 

According to the Joint Chiefs of Staff, the North fired at least one unidentified projectile from Sino-ri, North Pyongan Province at around 4:30 p.m, local time. 

A senior member of the South Korean ruling bloc said it was presumed to be a single projectile, adding it flew around 420 kilometers before splashing into the East Sea.

The launch came just five days after the regime fired around 20 projectiles and at least one tactical guided weapon into the East Sea. North Korea said on Wednesday that Saturday's drill was defensive in nature.