(CNN) Hours before they are due to start, possible joint military talks between North Korea and South Korea remain up in the air, with Pyongyang having yet to confirm its attendance.

The talks were proposed for Friday, near the demilitarized border that divides the two nations, but with the clock ticking down, the South Korean defense ministry said they would give their North Korean counterparts until Thursday afternoon local time to respond.

"We are still waiting for North Korea's official position," Moon Sang-gyun, a spokesman for the South Korean Defense Ministry, said at a Thursday briefing. "The administrative preparation for the talks from our side is in progress and going smoothly."

The news comes amid US suspicions that North Korea could be preparing for a new missile test, and as US defense officials said a North Korean submarine had been spotted engaging in "unusual activity" in international waters.

2020 hopes

Though the South Korean military has made similar overtures to the North before, the invitation is symbolic of President Moon Jae-in's hope of bringing about denuclearization on the Korean peninsula through dialogue and cooperation.

Moon, who was inaugurated in May, campaigned on a platform of engagement, in stark contrast to his hawkish predecessor, though pre-election opinion polls showed security was not the top issue for the electorate.

The proposal for talks came the same month as North Korea said it conducted its first successful test of an intercontinental ballistic missile (ICBM), a long-range weapon that could reach Alaska once it becomes operational.

Shortly after that test, Moon said he'd be willing to meet North Korean leader Kim Jong Un "at any time, at any place" -- circumstances permitting.

Moon's office released a policy roadmap for his five-year term this week, saying it hopes to reach "complete denuclearization" by 2020.

"We will come up with a comprehensive denuclearization negotiation plan that will lead to a nuclear freeze and a complete dismantlement of nuclear programs. We will resume negotiations for comprehensive denuclearization," the report said.

If those conditions are met, South Korea would willing to sign a peace treaty with the North, according to the report. The two countries are technically still at war, as hostilities during the Korean War ended with an armistice rather than a formal peace treaty.

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But it's unclear exactly how the Moon administration plans to get North Korea to give up its nukes.

Pyongyang has long insisted that its nuclear weapons are here to stay, as North Korea believes its ability to use nukes against the United States is the key to preventing any American-led efforts at regime change.

"Unless a fundamental end is put to the US hostile policy toward the DPRK (Democratic People's Republic of Korea, North Korea's official name) and the nuclear threat to it, the DPRK will never put the nuke and ballistic rocket on the negotiating table," state-run KCNA said in a commentary the day after the July 4 ICBM launch.

'Nonsensical and acting deceptively'

North Korea has not officially responded to either the denuclearization plan or the potential talks, but a commentary piece published in North Korean state-run newspaper Rodong Sinmun called the proposal disingenuous. It said South Korea needs to end its "anti-North Korean confrontations and hostile practices" in order to improve inter-Korean relations.

"South Korean authorities can only be viewed as nonsensical and acting deceptively towards the public by mentioning 'improving ties,' while they are still showing hostility and making confrontational attempts against North Korea," wrote the author, identified as Ra Sol Ha.

North Korea often uses hostile, harsh rhetoric in state media when speaking about its adversaries. Though there are propaganda benefits associated with strong uncompromising verbiage, analysts believe that North Korea uses this type of exaggerated bluster as a means of improving its hand during possible future negotiations.

Though Moon has advocated for more engagement, the prospects of all sides getting to the negotiating table soon on good terms is dim.

The administration of US President Donald Trump says it'll only engage in talks under the right conditions, which likely means that any negotiations will be contingent on North Korea agreeing to put denuclearization on the table.