The US and North Korean leaders met in Vietnam last week (Picture: PA).
South Korea has proposed semi-official three-way talks with the US and North Korea as it struggles to put nuclear diplomacy back on track after the collapse of a summit between Donald Trump and North Korean leader Kim Jong Un.
South Korean President Moon Jae-in led a National Security Council meeting to discuss South Korea's diplomatic strategy following the breakdown of a high-stakes summit between US President Donald Trump and North Korean leader Kim Jong Un last week in Vietnam.
Mr Moon lobbied hard for the revival of nuclear diplomacy between Washington and Pyongyang following a period of tension over the North's missile and nuclear tests and Mr Trump's threats to bring down "fire and fury" on North Korea.
But experts say the breakdown of the meeting in Hanoi has put the credibility of Mr Moon's role as mediator in doubt.
"We hope that both countries will continue their dialogue and that their leaders meet again quickly to reach an agreement that was held off this time," Mr Moon said.
"In the process, our role has become important once again.
"While I believe the United States-North Korea negotiations will eventually reach an agreement, it's never desirable for a vacuum in dialogue or stalemate to prolong."
The reason I do not want military drills with South Korea is to save hundreds of millions of dollars for the U.S. for which we are not reimbursed. That was my position long before I became President. Also, reducing tensions with North Korea at this time is a good thing!— Donald J. Trump (@realDonaldTrump) March 3, 2019
On Sunday, Donald Trump tweeted to say "reducing tensions with North Korea at this time is a good thing".
Mr Moon said Seoul will continue to push ahead with inter-Korean engagement within the boundaries of US-led international sanctions against the North.
Mr Moon has prioritised stabilising bilateral relations with the North amid the larger nuclear negotiations between Washington and Pyongyang, saying inter-Korean reconciliation will drive nuclear progress.
But his call for partial sanctions relief to push the North towards disarmament steps has caused disagreements with Washington, which sees economic pressure as its main leverage with Pyongyang.
Mr Moon helped set up the first meeting between Mr Trump and Mr Kim last June when they agreed to a vague aspirational statement about a nuclear-free Korean Peninsula without describing how and when it would occur.
Still, Washington and Seoul are committed to keeping an atmosphere of dialogue alive and announced on Sunday that they will not hold their usual large springtime military drills, replacing them instead with smaller exercises in what they call an effort to support diplomacy with Pyongyang.