His visit comes amid a near seven-week hiatus in the North's sabre-rattling. There have been no provocations since Sept. 15, when it test-launched a ballistic missile over Japan.

The unusually long hiatus has kindled cautious hopes of a window opportunity in which to conduct diplomacy with the recalcitrant regime.

"North Korea will be watching closely every step President Trump takes (during the trip). ... It will likely have an impact on the level or the timing of future provocations North Korea could take," Kim Yong-hyun, a professor of North Korean studies at Seoul's Dongguk University, said.

The best scenario would be Trump's abstention from making aggressive remarks and North Korea's continued refraining from provocations and its subsequent participation in the PyeongChang 2018 Winter Olympics in South Korea, analysts say.

Still, they do not rule out the possibility of North Korea resuming its military provocations before or during Trump's Asia trip, as its leader Kim Jong-un had threatened to take "the strongest ever measure" in response to Trump's UN speech in September in which he called Kim "Rocket Man" and threatened to destroy North Korea if necessary.

In Seoul, Trump will give a speech at the National Assembly on Nov. 8, in which US officials have said he will call on the international community to join efforts to inflict maximum pressure on North Korea. The tone and manner of Trump's talk on the North will be the subject of intense attention.

Whether Trump and Moon will speak in a fully united voice during their summit meeting is also a point of concern. They have both vowed to denuclearize North Korea. But the US made it clear that military options are on the table as part of solution, while South Korea is opposed to any kind of war on the peninsula.

"Any concerns about dissonance between South Korea and the US would be dispelled if Trump delivers a peaceful message that the US does not want war or an escalation of tension but instead will apply maximum pressure," Kim Hyun-wook, a professor at the Korea National Diplomatic Academy, said.

The North Korea nuclear issue will obviously take center stage during Trump's summit meeting with Chinese President Xi Jinping as Trump seeks to mobilize the leverage China has over North Korea.

"There's a possibility that China would step up sanctions against North Korea through cooperation with the US, but we cannot rule out the opposite possibility of China expanding its engagement with North Korea by mending ties with the country," said Jun Byoung-kon, researcher at the Korea Institute for National Unification. (Yonhap)