President Yoon Suk Yeol passes by a transporter erector launcher carrying the Hyunmoo-5 ballistic missile during a ceremony marking Armed Forces Day, Oct. 1, at Seoul Air Base in Seongnam, just south of the capital. Yonhap

South Korea showcased its most powerful missile for the first time Tuesday as it marked Armed Forces Day in an apparent warning against North Korea's nuclear and missile threats.

Two mobile missile launchers carrying the Hyunmoo-5, a centerpiece of South Korea's retaliation plan against a major North Korean attack, were among military equipment displayed at a ceremony at Seoul Air Base in Seongnam, just south of the capital.

The ground-to-ground ballistic missile, dubbed a monster for its size, had been shrouded in secrecy due to its strategic importance. It is known to be able to carry a warhead weighing about 8 tons and capable of destroying underground bunkers.

South Korea has developed a series of Hyunmoo missiles, including ballistic and cruise-type ones. It unveiled the Hyunmoo-4 during last year's Armed Forces Day ceremony. That missile, however, can only deliver a payload of about two tons in comparison.

During this year's ceremony, the 9-axled transporter erector launchers crawled across the tarmac, each of them carrying a canister estimated to be about 20 meters long, apparently housing the "high-power" and "high-precision" missile known to be able to target anywhere in North Korea.

In another show of force, a U.S. B-1B heavy bomber flew over the air base, alongside two F-15K jets, in a display of the U.S. security commitment to South Korea. North Korea earlier warned of taking a "corresponding" measure against the deployment of U.S. strategic assets.

Some 5,000 troops and hundreds of pieces of military equipment were gathered for the ceremony, marking the 76th founding anniversary of the country's armed forces this year.

Special operations troops showed off their infiltration skills as they jumped out of a transport aircraft over the air base, while Apache attack helicopters fired flares and demonstrated evasion maneuvers as Richard Wagner's "Ride of the Valkyries" blasted in the background.

An Apache attack helicopter fires flares as it takes part in the Armed Forces Day ceremony at Seoul Air Base in Seongnam, Gyeonggi Province, Oct. 1. Yonhap

The military also showed off various air assets, including the KF-21 fighter currently under development and F-35A stealth jets, while the Air Force's Black Eagles aerobatic team performed a series of air maneuvers.

This year's ceremony came as North Korea has ramped up tensions in recent weeks ahead of the upcoming U.S. election, disclosing its uranium enrichment facility, launching ballistic missiles and flying trash-carrying balloons across the border.

The defense ministry said Tuesday's event was organized to show its "overwhelming" capabilities to powerfully retaliate against potential enemy provocations, backed by the country's three-axis deterrence structure.

The three-pronged system refers to the Korea Massive Punishment and Retaliation, an operational plan to incapacitate the North Korean leadership in a major conflict; the Kill Chain preemptive strike platform; and the Korea Air and Missile Defense system.

Officials said this year's ceremony also mobilized an expanded lineup of assets that require the teaming of manned and unmanned operations, such as quadruped robots as well as an unmanned submarine and surface vehicle.

A military parade was set to take place in downtown Seoul on Tuesday afternoon, marking the second consecutive year troops have marched through the capital's center.

The country has usually marked its military founding anniversary in time for Armed Forces Day, which commemorates the service of military personnel and falls on Oct. 1. (Yonhap)