Seoul: South Korea on Tuesday rejected North Korea's proposal to hold a meeting of political parties and social organisations around August 15 marking the 71st anniversary of the peninsula's liberation from Japan's 1910-45 colonial rule. Seoul's unification ministry said North Korea's offer was propaganda ploy against South Korea, Xinhua news agency reported. A ministry statement said Pyongyang's dialogue offer lacked sincerity as it came amid the ongoing nuclear test and missile launches. The statement came a day after North Korea proposed holding a grand meeting with South Korea for unification and unity. Pyongyang said the meeting will be attended by political parties, social organisations and individual figures, before or after August 15. Pyongyang offered to hold a working-level contact in July to discuss the issue. The statement said if Pyongyang has any sincerity in pursuing peaceful unification on the peninsula and improving inter-Korean relations, it should show its commitment to denuclearisation with actions. Following its historic Worker's Party of Korea (WPK) congress in early May, North Korea had proposed holding a dialogue with South Korea to ease tensions on the peninsula. Seoul has rejected the dialogue overtures, urging Pyongyang to show its will to denuclearise first before any dialogue is to be held between the two sides. North Korea conducted its fourth nuclear test in January, followed in February by a launch of a long-range rocket, which was condemned as a disguised test of ballistic missile technology. On June 23, Pyongyang test-fired its surface-to-surface strategic ballistic missile Hwasong-10, called in South Korea Musudan intermediate-range ballistic missile, and said it was successful as the missile flew about 400 km after being propelled as high as 1,413.6 km. UN Security Council resolutions ban any North Korea test of ballistic missile technology.