SEOUL, South Korea -- South Korean President Yoon Suk-yeol said Wednesday he would consider suspending a 2018 agreement that created maritime buffer zones with the North should Pyongyang "violate" Seoul's territory again.

The deal, struck during a period of high-profile diplomacy at a summit in Pyongyang, aimed to reduce military tensions along the heavily fortified border.

At the time, the two sides agreed to "cease various military exercises aimed at each other along the military demarcation line", but Pyongyang began repeatedly violating the deal last year.

North Korea fired artillery shots into the agreement's designated maritime buffer zones multiple times in 2022, and last week sent five drones across the border into South Korean airspace.

The violations have prompted growing calls from ruling-party parliamentarians for the hawkish Yoon administration to scrap the four-year-old deal, inked under then-president Moon Jae-in.

On Wednesday, Yoon instructed his security aides "to consider suspending the military agreement if the North carries out another provocation violating our territory," spokeswoman Kim Eun-hye told reporters.

Yoon also called for "a large-scale production of small-size drones that are hard to be detected by the end of the year" and the creation of a multi-purpose drone unit for an "overwhelming counter-offensive capability".

The North Korean drone incursion, the first such incident in five years, prompted an apology from Seoul's defence minister after the military failed to shoot down any of the unmanned aircraft despite scrambling jets for a five-hour operation.

Scrapping the 2018 deal would "increase the chance of heightened military tensions and an actual clash in border areas", Hong Min of the Korea Institute for National Unification told AFP.

Despite Pyongyang violating the deal, the agreement still helped with "preventing a major military clash," he said.

"It will be a much different story if Yoon puts an official, political end to the agreement".