Cheong Wa Dae said Saturday that North Korea's latest firing of unidentified projectiles into the East Sea is an apparent show of force against the joint military exercise between Seoul and Washington slated for next week.

Two short-range projectiles were fired from near its eastern coastal city of Hamhung in South Hamgyong Province earlier in the day.

The South Korean military said the projectiles are presumed to be short-range ballistic missiles, which flew 400 kilometers with a peak altitude of 48 km.

It is the regime's fifth launch in just over two weeks.

Right after the firing, head of the presidential National Security Office Chung Eui-yong held a meeting with Defense Minister Jeong Kyeong-doo and National Intelligence Service Director Suh Hoon.

"They believed that the moves are apparently a show of force against the combined military exercise between South Korea and the US scheduled on Sunday," Cheong Wa Dae spokesperson Ko Min-jung said in a release.

The computer-based "Combined Command Post Training" will be conducted for 10 days starting Sunday, which aims to better prepare the allies for the transfer of the wartime operational control (OPCON) from Washington to Seoul and to enhance their strong military readiness. 

The officials also said the Saturday firing is aimed at testing the capabilities of its newly developed short-range projectiles.

"They called on the North to stop launching missiles as the recent series of provocative movements may escalate military tensions on the Korean Peninsula," Ko said.

They vowed to reinforce the defense posture and tighten the alliance between South Korea and the United States through the joint military drill, she said. (Yonhap)