President Moon Jae-in on Wednesday called on his country's military and allied US forces here to be fully ready to counter any possible provocations from communist North Korea, partly reiterating the defensive nature of their ongoing joint exercise here.

"Thanks to you, all our people can live their daily lives, and we deeply trust and take pride in your sacrifice to the nation," the president said during a visit to the wartime command center earlier in the day, according to his spokesman Park Soo-hyun.

South Korean and US forces are currently staging their annual military exercise, known as the Ulchi Freedom Guardian, that will last until next Thursday.

Moon's visit to the center followed Pyongyang's renewed accusation that the joint military exercise was a rehearsal for their planned invasion of the communist state.

Seoul has repeatedly said the annual military drill has been and remains completely defensive in nature.

In his recent speech marking the 72nd anniversary of Korea's liberation from the 1910-45 Japanese colonial rule last week, the South Korean president also said his country does not want "North Korea to collapse."

Moon urged the joint forces to be fully prepared to counter any military provocation by the North.

"I ask you to maintain a complete defense readiness in case North Korea might actually make another provocation even during the exercise," the president was quoted as saying.

North Korea has staged 12 missile tests since the start of this year, including seven missile launches that took place after Moon came into office on May 10.

The president also called for efforts to maximize the outcome of the ongoing defensive drill that also involves all government offices, including provincial and district offices.

"Modern warfare requires all national resources, and we can ensure synergy effect when all components, including the military, central government and local governments, produce integrated abilities," the president told military commanders at the center, according to his spokesman.

The exact location of the center is highly classified information and thus was not released. (Yonhap)