Presidential hopefuls from the liberal bloc plan to visit military facilities Wednesday, in an apparent bid to highlight their interest in national security and curb perceptions the opposition parties are less concerned about Pyongyang's provocations.

Rep. Ahn Cheol-soo, a potential candidate from the minor People's Party, plans to visit the Joint Chiefs of Staff in central Seoul, amid rising concerns that North Korea may test an intercontinental ballistic missile.

Military officials will brief Ahn on preparations against North Korea's provocations, as well as other key agenda items related to the Seoul-Washington alliance.

Moon Jae-in, a leading potential candidate from the main opposition Democratic Party, headed to Gangwon Province on Wednesday to visit front-line military bases.

Political pundits said the potential candidates' visit to military facilities falls in line with the efforts to grab conservative and neutral voters, who cast concern over the liberal bloc's normally dovish policies on North Korea.

As South Korea is still technically at war with Pyongyang, presidential candidates' stance on North Korea has always been an important issue in previous elections.

Last year, Moon took flak for allegedly playing a part in contacting Pyongyang and getting feedback that was then reflected in Seoul's decision-making process on a UN vote. 

In a memoir, a former foreign minister claimed Seoul abstained from voting on the 2007 UN resolution on North Korea's human rights after hearing Pyongyang's views, and that Moon was involved in contacting the North. 

Moon has maintained that he did nothing to hurt the country's security or acted favorably toward Pyongyang. (Yonhap)