SEOUL - South Korea will expand cooperation with China and the United States to achieve a goal of the Korean Peninsula denuclearization, the Foreign Ministry said Monday in its annual report to President Park Geun-hye.

Under the principle of "opening a unification era" through diplomacy, the ministry aims to prevent the nuclear program of the Democratic People's Republic of Korea (DPRK) from worsening inter- Korean relations.

The ministry anticipates a virtuous cycle, in which improved inter-Korean ties help denuclearize the peninsula and the denuclearization efforts help enhance inter-Korean relations further.

South Korea proposed to hold a dialogue in January with the DPRK to discuss all issues of mutual concern, but Pyongyang kept mum about it.

Seoul plans to deter the DPRK from conducting the fourth nuclear test, by strengthening strategic cooperation with China and the United States. Pyongyang detonated atomic devices in 2006, 2009 and 2013.

For the deterrence, South Korea will make aggressive efforts to resume the long-stalled six-party talks, which involve China, the United States, Russia and Japan as well as the two Koreas. It was initiated in Beijing in August 2003 but has been halted since December 2008.

The DPRK offered to temporarily suspend nuclear tests if the United States halts joint annual military exercises with South Korea this year, but Washington refused it.