Pyongyang last month put a military spy satellite into orbit and has since said that its eye in the sky was providing images of major US and South Korean military sites.

The event has fractured an inter-Korean military agreement established to de-escalate tensions on the peninsula, with both countries ramping up security along the Demilitarized Zone (DMZ) separating them.

"If North Korea does something reckless that destroys peace, all that awaits them is a hell of destruction," Defence Minister Shin Won-sik said in a meeting with top military commanders.

Shin has recently made unusually fiery remarks and last week threatened lethal missile strikes on "the heart and head" of Pyongyang in the event of a war.

Seoul, Tokyo and Washington announced last week that they have launched "new trilateral initiatives" to counter Pyongyang, including a real-time data-sharing operation on North Korean missile launches.

The three allies have spearheaded worldwide censure of Pyongyang for breaching several UN Security Council resolutions with its November satellite launch.

The resolutions bar North Korea from tests using ballistic technology, used in both missiles and space launch rockets.

The allies said last week that the new initiatives encompass measures to address Pyongyang's cybercrime, cryptocurrency, and money laundering activities, which are believed to fund North Korea's nuclear and missile programmes.

Shin on Wednesday criticised the previous South Korean administration's pacifist approach to Pyongyang, calling it a "well-orchestrated scam".

It was during the dovish former president Moon Jae-in's tenure that the recently broken inter-Korean military agreement was signed.

Seoul and Washington are scheduled to conduct discussions on nuclear deterrence this Friday.