Images have emerged of North Korea's biggest ever artillery drill that marked the 85th anniversary of its military's creation.

Massed ranks of guns can be seen lining a beach as flame blossoms from their barrels. Dictator Kim Jong-un was also pictured overseeing the action in images from the North's state-run media.

It is thought that between 300 and 400 artillery pieces were used in the demonstration, held near the eastern port city of Wonsan.

On Tuesday, North Korea's state media was defiant in a commentary marking the 85th anniversary of the foundation of the Korean People's Army, saying its military was prepared "to bring to closure the history of US scheming and nuclear blackmail".

"There is no limit to the strike power of the People's Army armed with our style of cutting-edge military equipment including various precision and miniaturised nuclear weapons and submarine-launched ballistic missiles," the official Rodong Sinmun newspaper said in a front-page editorial.

It is believed the North has a large number of artillery pieces trained permanently on Seoul.

"The latest fire drill is seen as part of North Korea's wrap-up of a months-long winter training program," Professor Kim Dong-yub of Kyungnam University told South Korea's Yonhap news agency.

It came at a time of heightened tension as US President Donald Trump attempts to persuade China to rein in its neighbour.