In the afternoon, he is set to visit a fire-ravaged market in Daegu, 302 kilometers south of Seoul, which has long been considered a stronghold for conservatives. 

Ban's potential allies and rivals have closely watched his politically tinged tour, as he has emerged as a powerful presidential contender likely to represent the conservative bloc.

In various opinion polls, Ban has ranked second, trailing Moon Jae-in, a former leader of the main opposition Democratic Party.

At the Gwangju cemetery, Ban hailed the city as the "birthplace of South Korea's democracy."

 "We must not take the democracy we enjoy for granted, as this has come after the painful sacrifices," Ban told reporters after he paid homage to the fallen democracy fighters. "We must make constant efforts to further develop our democracy."

Mentioning a series of economic and political challenges facing the country, Ban said, "If we join hands, there is nothing that we cannot overcome. I, as a former UN secretary-general, will continue to help advance our country, though my capacity is limited."

Ban, then, moved to Chosun University in the city to deliver a lecture, where he underscored the need for the government to prioritize creating jobs for young people.

"Government leaders must put a top policy priority (on creating jobs and handling other issues facing young adults)," he said during the lecture. "If necessary, we need to institute a special (government) division or a top official that handle the issues."

Touching on citizens' anger and frustration at the country's scandal-tainted leadership, Ban pledged to become an "inclusive" leader.

"A leader in a country that has achieved a mature democracy must seek inclusive dialogue with citizens from all walks of life, and we also need inclusive growth," he said. "This is what we need now, and this is what citizens wish for."

Ban also reiterated his support for the planned deployment of a US missile defense system to South Korea, saying China's opposition to it can be addressed through diplomacy.

Beijing has vehemently opposed the plan to install a Terminal High-Altitude Area Defense system on the peninsula, arguing that it would undermine its strategic security interests. 

"THAAD is purely for a defense purpose. It is not for any offensive purpose," he said. 

"There is no such thing as a second chance when it comes to security, though we can seek a change in economic and social policies when they don't work well... When you lose security once, it is the end," he added.

Later in the day, he visited a fish market in Yeosu, 455 kilometers south of Seoul, before his trip to Daegu. A large part of the market, a traditional tourist attraction, was gutted by a fire last weekend.

On Thursday, Ban plans to pay a courtesy call to former President Lee Myung-bak and Son Myung-soon, the wife of late President Kim Young-sam, both in Seoul.