The previous rounds, which occurred from its eastern regions under the guidance of leader Kim Jong-un, appear to have been part of its artillery strike drill for the wintertime exercise, JCS officers said, noting that the drill is likely to continue throughout this month.
According to the North's official Korean Central News Agency (KCNA) on Saturday, North Korea held an "artillery fire competition" of its army on its western front the previous day under Kim's watch.
Of 13 rounds of weapons tests carried out throughout 2019, the May 9 test took place in North Pyongan Province, when the North fired two projectiles believed to be its version of Russia's Iskander ballistic missiles.
Its adjacent South Pyongan Province was also the venue for two other tests -- held in September and October -- when it fired two projectiles each from its super-large multiple launcher system.
North Korea has often brought its weapons to western regions and had them fly all the way across its territory before splashing into the East Sea in a move to verify their reliability, according to experts.
Watchers say the recent military moves appear to have been intended to beef up leader Kim's internal grip on power amid fears over the spread of COVID-19 and economic difficulties.
The North is struggling to contain the novel coronavirus which has swept through the whole world, though Pyongyang has said that it has not reported a single confirmed case, a claim doubted by many.
In the face of prolonged international sanctions amid the stalled denuclearization talks with the United States, the regime has also called for boosting self-defense capabilities.
In his New Year's Day message, leader Kim warned he will show off a "new strategic weapon" in the near future, which experts said may mean an advanced type of its intercontinental ballistic missile (ICBM) or a submarine-launched ballistic missile (SLBM).
Instead of completely turning away from dialogue, however, the North appears to have taken low-intensity steps, though it is banned from all ballistic missile activity under U.N. Security Council resolutions. (Yonhap)