People watch a TV screen showing a file image of a North Korean missile in a military parade during a news program at the Seoul Railway Station in Seoul, South Korea, Auguts 30, 2021. (Photo: AP)

In its defence blueprint for 2022-2026, the defence ministry said it would develop new missiles "with significantly enhanced destructive power," upgrade missile defence systems and deploy new interceptors against long-range artillery.

The ministry said in a statement that it will develop stronger, longer-range and more precise missiles so as to exercise deterrence and achieve security and peace on the Korean Peninsula.

Among those missiles is a new weapon with a flight range of 350-400 kilometres and a payload of up to 3 tons, designed to destroy underground facilities, Yonhap reported.

The missile would be the latest in a tit-for-tat conventional missile race between the two Koreas that is set to accelerate after South Korea and the US agreed to scrap all bilateral restrictions on Seoul's missile development earlier this year.