North Korea has annulled a five-year-old agreement with Seoul aimed at reducing military tensions, marking a further escalation in the ongoing dispute between the two nations.

The conflict arose when Pyongyang declared the successful launch of a spy satellite into space on Tuesday. In response, South Korea partially suspended the agreement, announcing the resumption of surveillance flights along the border.

In retaliation, Pyongyang has now declared a complete suspension of the pact, pledging to deploy stronger forces and advanced equipment to the border.

In a statement, North Korea declared, "Our army will no longer be constrained by the September 19 North-South Military Agreement."

The regime vowed to retract all measures previously implemented to prevent military conflict across various domains, including ground, sea, and air. Additionally, North Korea plans to deploy "more potent armed forces and new-generation military hardware" in the border region.

The heightened tension followed Pyongyang's launch of a rocket, believed to carry the Malligyong-1 spy satellite, late on Tuesday, which the regime hailed as a "success."

South Korea's military later confirmed that the satellite had entered orbit but said it was too soon to tell if it was actually functioning.

Seoul strongly condemned the launch - and on Wednesday morning top officials agreed to immediately restart surveillance operations along the border, which would allow the South to monitor North Korean outposts and long-range artillery.

That is a breach of a no-fly zone established under the Comprehensive Military Agreement in 2018 - signed by both nations' leaders to de-escalate tensions between their two countries and prevent a conflict from erupting.

A US official said the South Korean decision to suspend part of the agreement was a "prudent" response, citing the North's "failure to adhere" to the pact.

The following morning, North Korea said it would restore all conflict-avoiding measures it had halted under the deal, and said Seoul would face the blame if a clash broke out.

Its statement came hours after it fired a ballistic missile into the sea east of the Korean peninsula - its first known weapons firing in more than two months. The South Korean military said the missile was likely to have failed.

Pyongyang insists the launch of the spy satellite is part of its "right to self-defence" - but South Korea, the we, and Japan have strongly condemned it.

Developing a functioning spy satellite is a major part of North Korea's five-year military plan, set out by its leader Kim Jong Un in January 2021.

The technology could in theory enable Pyongyang to monitor the movement of US and South Korean troops and weapons on the Korean Peninsula, allowing it to spot incoming threats. It would also allow the North to plot its nuclear attacks more precisely.

North Korean state media has claimed the country's leader Kim Jong Un is already reviewing images of US military bases in Guam sent by the new satellite. The BBC has not verified this.

Noted