He was attending a national ceremony to commemorate a historic incident in the annals of the country's democracy: the Busan-Masan Democratic Protests of 1979.
"Now, the people are calling for more democracy and better democracy," the president said in his speech at the ceremony to mark the 40th anniversary of the public uprising against the authoritarian rule of President Park Chung-hee.
He added, "All powerful government institutions should bear the common sense in mind that they exist for the sake of the people, not for the sake of their organizations."
"Our democracy has been developing and growing with no break.When democracy was in crisis, the people saved democracy with action," he said.
His remarks came amid the government's push for the reform of the prosecution, which many people regard as having excessive power and authority.
Moon appointed Cho Kuk, one of his political allies, as justice minister in September, giving him a mandate to complete prosecution reform. Cho stepped down earlier this week, however, after weeks of rallies for and against him amid allegations of ethical lapses and financial wrongdoing in his family.
On Oct. 16, 1979, some college students started a protest in Busan against the Park regime, and then a larger number of citizens in the city as well as nearby Masan, which is currently called Changwon due to an administrative district change, joined it for days.
The move is said to have prompted an end to Park's dictatorship. Park was assassinated by his top aide on Oct. 26 that year.
In a Cabinet meeting last month, the liberal Moon administration designated the anniversary of the Busan-Masan Democratic Protests as a national memorial day, a show of its efforts to highlight the historic value and meaning of the democratic movement.
It also formally acknowledged a 51-year-old man as a victim of the suppression of the movement. He is the first and only victim officially recognized by the government in connection with the use of force against participants in the protest.
Moon pointed out that there has been a longtime lack of state-level compensation for those who were killed or wounded in the suppression of the movement.
"As the president, I would like to express my deep condolences and apologies to all of the victims whose human rights were abused by the Park regime," he said.
Moon described the site of the protests as a "holy place" of the nation's democracy, addressing the ceremony held at Kyungnam University in Changwon, South Gyeongsang Province, 400 kilometers south of Seoul.
Moon emphasized that no powerful government agency will be able to "reign over the people" as long as South Korea has such great historic assets as the April 19 Revolution, the Busan-Masan Democratic Protests, the May 18 Democratic Movement, the June 10 Struggle and the massive candlelight vigils of 2016.
He was referring to major public anti-government protests in the modern history of South Korea.
Busan is Moon's hometown but it is a traditional stronghold of the conservative Liberty Korea Party, along with Changwon.
The main opposition party's leader, Hwang Kyo-ah, was present at the anniversary event as well. (Yonhap)