SEOUL (THE KOREA HERALD/ASIA NEWS NETWORK) - Over the past week, North Korea has alternated between conciliatory gestures and provocative acts.

On Monday (March 9), the North fired three projectiles off its east coast in what it said was an artillery strike drill involving multiple rocket launchers.

It was the second time in a week that the North had tested weapons. Previously, on Mar 2, it fired two projectiles for the first time in about three months.

Despite Pyongyang's description of the projectiles as "long-range artillery pieces," Seoul's defence officials view them as de facto short-range ballistic missiles.

North Korean leader Kim Jong Un supervised both artillery strike drills, according to the regime's propaganda machine.

In the interval between the test-firings, Mr Kim sent a personal letter to President Moon Jae-in on Mar 4, wishing him and other South Koreans good health amid the massive outbreak of the novel coronavirus.

The apparent reconciliatory gesture came as a surprise because it occurred just one day after Kim Yo Jong, the North Korean dictator's sister and close aide, issued a harshly worded statement criticising Moon's office for voicing "strong concerns" over the short-range missile tests.

Though she did not criticise President Moon directly, her words cast a cloud over hopes of improving the strained ties between the two Koreas.

Inter-Korean exchanges have been at a standstill as Pyongyang remains unresponsive to Seoul's offers to engage in talks and cooperation.

In his March 1 speech commemorating the 1919 uprising against Japan's colonial rule of the peninsula, Mr Moon proposed cooperation with the North in the health care sector.

Pyongyang has remained mum on Mr Moon's latest overture, answering it with missile launches and a virulent statement against Seoul denouncing its provocation.

Yet South Korea's presidential office appeared buoyed by Mr Kim's letter.

A spokesperson for Mr Moon said the North Korean leader showed his constant friendship and trust toward Moon and revealed his "frank" thoughts about the situation on the peninsula. Cheong Wa Dae did not elaborate on Mr Kim's thoughts.

Mr Moon sent a reply to Mr Kim thanking him for his support.

But Monday's missile launches by the North embarrassed the Moon administration again.

Mr Moon's office said the move would not help bring peace to the peninsula, stopping short of expressing strong concerns as it had a week earlier.

Some critical observers here say Mr Moon and his security aides seem to have been tamed by Mr Kim and his sister's tactic of pairing provocative acts with conciliatory gestures.

It is notable that North Korea's state media have not yet reported on the letter Mr Kim sent Mr Moon, possibly suggesting deception behind the seemingly conciliatory move.

Seoul officials in charge of inter-Korean relations say the North's recent artillery drills appear aimed at drawing attention from South Korea and the US and pressuring Washington in particular to change its approach to Pyongyang.

Denuclearisation talks between Washington and Pyongyang have stalled since the second summit between US President Donald Trump and Mr Kim ended with no deal in Hanoi in February 2019.

The US has refused to ease economic sanctions against the North without substantial progress in denuclearising the recalcitrant regime, and has cautioned Seoul against being overeager to push for inter-Korean projects.

The North's recent missile firings show that it continues to upgrade its capabilities to strike key targets in the South, including US military bases.

Experts here express concerns that it would be practically impossible to defend against the North's short-range ballistic missiles if they were fired at short intervals along with other artillery pieces.

US Defence Secretary Mark Esper said during a recent Senate Armed Services Committee hearing that North Korea's ballistic missile capabilities are becoming "increasingly complicated" as the regime seeks to modernise the full range of its missile systems.

Pyongyang's enhanced missile systems could nullify South Korea's preemptive strike program, called Kill Chain, leaving it with no effective means to deter missile attacks from the North.

The Moon government should be firm in warning Pyongyang against taking any further provocative moves and should strengthen South Korea's missile defence systems.

Mr Moon himself needs to issue a warning message if the North repeats these provocations down the road.

He should depart from his preoccupation with short-term accomplishments in cross-border ties at the risk of endangering the South's security posture against the North.

No one here wants to see the Moon government being derided again by Pyongyang as looking like a "scared dog."

The Korea Herald is a member of The Straits Times media partner Asia News Network, an alliance of 24 news media organisations.