North Korea's invitation to South Korean President Moon Jae In to visit Pyongyang, which marked the climax of its Olympic charm offensive, puts him in the delicate position of needing to maintain the conciliatory mood on the Korean Peninsula while keeping intact his country's alliance with the United States.

Whether or when Seoul and Washington will carry out annual joint military exercises that were delayed until after the Olympics and Paralympics is a looming challenge for the Moon administration, Korea experts say.

(U.S.-South Korea live-fire drills in April 2017)

North Korean leader Kim Jong Un launched the charm offensive in his New Year's address, when he expressed willingness to send athletes to the Pyeongchang Winter Olympics.

The two Koreas subsequently agreed to march together under a unified flag in the Feb. 9 opening ceremony and field a joint women's ice hockey team.

North Korea's Olympic cheerleaders, dubbed the "army of beauties," were mobbed by the media, and the Samjiyon art troupe, including an orchestra, and a taekwondo team staged performances in South Korea in an apparent bid to soften the image of Kim's regime.

Most notably, a high-ranking delegation including the nation's ceremonial leader Kim Yong Nam and Kim Jong Un's younger sister, Kim Yo Jong, paid a visit to the South for the opening event and talks with Moon.

During their formal meeting at the Blue House, the presidential office, on Feb. 10, Kim Yo Jong, who described herself as her brother's special envoy, delivered a personal letter from him and invited Moon to visit the North.

The progressive president, who favors inter-Korea dialogue toward denuclearization of the peninsula, replied by saying the two sides should "create the right circumstances to make it happen."

He also encouraged Pyongyang to seek dialogue with Washington, saying, "To improve relations between the South and the North, it is absolutely necessary for the North and the United States to talk."

(U.S.-South Korea live-fire drills in April 2017)

Moon expects North Korea to show a goodwill gesture toward the United States aimed at resolving the ongoing nuclear standoff, and also hopes Washington will soften its stance to hold a dialogue with the North, now that he set the stage for the two countries to start talks, the experts say.

Although Moon and Kim Yo Jong met four times during the delegation's three-day visit, the president is believed to have not taken up the key issue of the North's nuclear development.

Yuki Asaba, a Korea expert at Japan's University of Niigata Prefecture, said it is natural for Moon's behavior to prompt the United States and Japan, which is also under the North's threats, to harbor suspicions whether South Korea is a trustworthy partner.

Multiple local media also warned the Moon administration to put priority on ties with Washington in dealing with the North Korean crisis. In its editorial Tuesday, the Korea Joongang Daily said, "Without progress in Washington-Pyongyang relations, inter-Korean summits cannot achieve much."

To that end, "Sufficient communication with Washington is a precondition for a successful summit between Moon and Kim," the English-language newspaper also said.

In an attempt to gain the understanding of relevant countries, Vice Unification Minister Chun Hae Sung met with senior Japanese, Chinese and U.S. envoys to Seoul this week to explain the results of the high-profile inter-Korea talks.

Signs of a possible easing of tensions have emerged from both Pyongyang and Washington in the wake of the talks.

Kim Jong Un on Monday expressed "satisfaction" over the delegation's visit and gave "practical instructions" to mend inter-Korean relations, according to the Korean Central News Agency, which did not specify the details. But security pundits suspect Pyongyang seeks to induce Seoul to take its side in a bid to hurt the U.S.-South Korean security relationship.

Meanwhile, U.S. Vice President Mike Pence, who attended the Olympic opening ceremony, has expressed readiness to hold direct talks with North Korea while maintaining maximum pressure on it, according to a news report earlier this week.

In a press conference Tuesday, U.S. State Department spokeswoman Heather Nauert also hinted at the possibility of Washington engaging in "preliminary" talks with the North.

But for now, it is impossible to predict how Washington and Pyongyang will act after the Olympics and Paralympics running through March 18, which have ushered in a de-escalation of tensions on the peninsula.

The immediate focus will be whether the United States and South Korea will resume the large-scale military drills, which they agreed to postpone until after the sporting events.

No announcement has been made as to when the exercises will be carried out, but speculation is growing that Seoul wants to delay them even further in hope of maintaining the reconciliatory momentum between the two Koreas.

On Friday, North Korea called on South Korea to abandon the drills, which it has long been opposed to and denounces as a pretext for an invasion.

But Asaba pointed out the joint drills were not planned amid growing military tensions in the region due to North Korea's provocative acts, but have been conducted on a regular basis.

"If South Korea proposes to cancel them, it would damage the U.S.-South Korean alliance, meaning North Korea's strategy to drive a wedge between them would be having an effect," he added.