President Moon Jae-in speaks during the graducation ceremony of the Korean Naval Academy in Jinhae, Tuesday. Yonhap

President Moon Jae-in reiterated his confidence in diplomatic efforts to denuclearize the Korean Peninsula Tuesday despite the fruitless summit between North Korea and the United States last week.

"Should we consistently pursue peace with firm determination, denuclearization of the Korean Peninsula and permanent peace will definitely come," the president said in the commission ceremony of the Korean Naval Academy in Jinhae, about 400 kilometers southeast of Seoul.

U.S. President Donald Trump and North Korean leader Kim Jong-un ended their second summit without an agreement in Hanoi last Thursday. Seoul had been highly hopeful that the summit would further advance the North's denuclearization process. Trump and Kim first met in Singapore in June.

On Monday, Moon also insisted the U.S. and North Korea will eventually reach an agreement, while chairing a National Security Council meeting for the first time in nearly nine months to seek ways to help bridge the gap between the two technically warring countries.

South Korea and the U.S. technically remain at war with North Korea as the 1950-53 Korean War ended only with an armistice. However, Seoul officials said the two Koreas made a de facto declaration of the war's end when they signed a military deal, which they said is tantamount to a "non-aggression" agreement, in September when Moon visited Pyongyang for his third and latest summit with Kim.

Shortly after his meeting with Kim in Hanoi ended abruptly, Trump asked the South Korean president to act as a mediator and help narrow the difference between his country and North Korea.

Moon has told his top government officials to seek ways to resume U.S.-North Korea denuclearization talks at an early date.

Foreign Minister Kang Kyung-wha said the country will push for the so-called 1.5-track talks of officials and experts from the two Koreas and the United States, similar to those held in Sweden shortly before the second U.S.-North Korea summit.

President Moon says his country is taking the fate of the Korean Peninsula into its own hands.

"We have embarked on a road to decide the fate of the Korean Peninsula by ourselves based on the great strength of our military," he told the graduation ceremony, according to a script of his congratulatory remarks released by his office Cheong Wa Dae.

Moon also reiterated his call for strong defense capabilities.

"We need stronger defense capabilities to be able to not only defend peace but also to make peace," he said.

"(The military) must be a military that will deter wars but win without fail when it must fight." (Yonhap)