SEOUL (THE KOREA HERALD/ASIA NEWS NETWORK) - Pyongyang last week threatened to scrap inter-Korean deals unless Seoul stops North Korean defectors from sending anti-North leaflets across the border into the communist state.

A statement issued by North Korean leader Kim Jong-un's sister Kim Yo-jong said the South Korean authorities would be forced to "pay a dear price" if they let the situation continue.

It mentioned the possibility of Pyongyang shuttering a joint industrial park in a town north of the border, closing an inter-Korean liaison office there and scrapping a military accord aimed at reducing tensions between the two Koreas.

The statement filled with invectives and derisions against defectors and the South Korean authorities went so far as to urge Seoul to enact a law banning defectors from flying anti-Pyongyang leaflets into the North.

The demand was viewed as an intervention in the South's internal affairs.

Many observers here expected Seoul to express regret over the North's statement.

But the response from President Moon Jae-in's government went beyond everyone's expectation.

Hours after Kim's statement was carried by the North's state-run news agency, the South's Unification Ministry held an unscheduled press briefing to say the government is working on a plan to legislate a ban on sending leaflets into the North.

A ministry spokesperson said any act that could cause tension near the border and pose a threat to the life and property of people living in nearby areas should be stopped.

He went further to say most of the leaflets ended up landing in the areas south of the border, causing environmental pollution and placing the burden on local residents to get rid of them.

An official at the presidential office, Cheong Wa Dae, later said sending anti-Pyongyang leaflets "is good for nothing," vowing to respond "sternly" to any behavior that could harm national security.

The Moon administration's accommodative stance on the North's statement contrasts with its silence on a string of provocative acts by Pyongyang that ignored the inter-Korean military pact signed in September 2018, which bans all hostile acts against each other.

In a meeting presided over by Kim Jong-un last month, North Korea's Central Military Commission discussed "new policies" to bolster the country's nuclear deterrence and strengthen its armed forces.

A former commander of US Forces Korea, retired General Walter Sharp, recently expressed worry that the North would soon launch a new submarine capable of carrying ballistic missiles.

Critics now say the Moon administration seems to regard leaflets flown by defectors into the North as a more serious threat to the security of the South than Pyongyang's increasingly sophisticated missiles that could be tipped with nuclear bombs.

The envisioned legislation to ban flying leaflets could spark an outcry over the possible infringement of the right to freedom of expression, which is guaranteed under South Korea's Constitution.

The Moon administration may become more active toward the enactment of the conceived law as the ruling party secured a dominant majority in April's parliamentary election. Still it needs to refrain from pushing through the legislation without being based on public consensus.

Sending leaflets into the North can hardly be deemed as a wrong act, as it helps ensure North Korean people's right to know.

A ruling party lawmaker argued Pyongyang's statement should not be seen as a threat but as a signal that it is ready to resume dialogue with the South.

The North has not responded to the Moon administration's repeated offers for cross-border cooperation amid stalled talks with the US on dismantling its nuclear arsenal.

It has complained about Seoul dragging its feet in restoring major inter-Korean projects out of concerns that it would violate US-led international sanctions.

As some suggest, Pyongyang might be sending a signal that it would be ready to return to talks with Seoul, if the Moon government goes to the length of banning what has touched a sensitive nerve of the repressive regime.

The Moon administration may well advise defector groups and other activist organisations here to be more cautious in sending leaflets into the North.

But it should not go against the essential and fundamental values of the South's basic law in order to cater to Pyongyang's disgruntlement.

Such a concession would only lead to more brazen attempts by the North to tame the South Korean government, making it harder to place the inter-Korean relations on a normal track in the long term.

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