North Korea on Tuesday marked the 85th founding anniversary of its military with a massive live-fire drill in an apparent show of force amid tensions over Pyongyang's nuclear and missile programs.

Instead of conducting a nuclear test or missile launch, North Korea staged a large-scale conventional firing drill near the eastern city of Wonsan on the Korean People's Army anniversary, according to the South Korean military.

Tensions on the Korean Peninsula have heightened amid concerns about the United States' possible pre-emptive strike against Pyongyang to counter its provocative acts. Speculation was rife that Pyongyang may conduct its sixth nuclear test or launch a long-range ballistic missile to mark its military event.

North Korea ratcheted up its bellicose rhetoric against Washington, warning that the US will have to choose between political and military surrender.

"If the US and warmongers run amok with a reckless preemptive strike, we will stage the most brutal punishment of a pre-emptive attack in the sky and land as well as at sea and from underwater without any warning or prior notice," said Rodong Sinmun, the mouthpiece of the ruling Workers' Party of Korea.

The North held a meeting on Monday to celebrate the KPA's anniversary, stressing that it is ready to respond to possible Washington military actions.

"If the enemies dare opt for the military adventure despite our repeated warnings, our armed forces will wipe the strongholds of aggression off the surface of the earth through the powerful preemptive nuclear attacks," said Pak Yong-sik, the minister of the armed forces.

North Korea boasted its nuclear explosion in 2016 and tests of missiles including a new intermediate-range ballistic missile dubbed Pukguksong-2, calling it "a nuclear power in the East."

"Thanks to having invincible military power, (North Korea) is successfully pushing forward the cause of building a socialist power, frustrating the hostile forces' madcap nuclear war provocations," the North's state news agency said.

Seoul's unification ministry said that North Korea does not seem to have any major events planned for the anniversary despite its war rhetoric.

"Another military parade is not expected, as North Korea already held a massive parade on the birthday of late state founder Kim Il-sung," said a military official. "Unusual movements are not detected in relation to the KPA anniversary."

North Korea unveiled prototypes of three intercontinental ballistic missiles in a show of force at a military parade held on April 15, the 105th birthday of Kim Il-sung, the grandfather of current leader Kim Jong-un.

Tensions are still running high as the US Navy strike group, including aircraft carrier Carl Vinson, is expected to sail near the Korean Peninsula this weekend.

The US flattop is expected to join military drills with the South Korean Navy in waters off the country's east coast, according to a military official. The USS Michigan, a submarine capable of launching missiles, also made a port call in South Korea earlier in the day.

North Korea's media warned that its military is ready to "sink" the carrier "with a single strike" if needed. (Yonhap)