North Korea on Monday celebrates the 90th anniversary of the founding of the Korean People's Revolutionary Army and the nuclear-armed country has staged military parades in the past to mark key holidays.

Pyongyang has carried out more than a dozen weapons tests this year, including firing an intercontinental ballistic missile at full range for the first time since 2017.

A report by the North's official Korean Central News Agency listed the history of the country's military achievements, from its battles against the United States in the 1950-53 Korean War to smaller conflicts.

"All the people of the country are looking back deeply on the history of the 100 victory of our revolutionary armed forces," it said.

The report added Kim had further propelled the country's military might with his "genius military ideology, excellent military command and unparalleled courage and guts".

"Our revolutionary armed forces have gained invincible power that the world cannot ignore," it said, in an apparent reference to the North's nuclear arsenal.

North Korea had been widely expected to showcase its military strength to mark the 110th anniversary of the birth of its founding leader and Kim's grandfather Kim Il Sung on April 15, but instead, the day was celebrated with a civilian parade.

Satellite imagery has shown continued preparations, with thousands of North Korean troops and scores of vehicles marching in formation at a parade training ground in Pyongyang.

"Typically, troops depart the training ground as soon as the parade is complete, so their presence further indicates an upcoming event," Martyn Williams, a fellow at the Stimson Center, wrote on the 38 North website.

US and South Korean officials and analysts have also warned Pyongyang could resume nuclear weapons testing for the first time since 2017, citing renewed activity at its key testing site.