North Korean leader Kim Jong-un has called for Seoul and its allies to take measures corresponding to steps taken by Pyongyang.
In his meeting with Chinese President Xi Jinping on Monday, Kim reiterated that denuclearization of the peninsula is the "will of the ancestors," but called on Seoul and Washington to take progressive steps.
The surprise meeting between Kim and Xi was held in Beijing, marking Kim's first trip outside North Korea since taking power in 2011. His visit was confirmed by Chinese and North Korean media on Wednesday.
Kim was accompanied by his wife Ri Sol-ju, and top-ranking officials including Choe Ryong-hae and Kim Yong-chol.
Choe is the vice chairman of the North Korean ruling party's central committee, and Kim Yong-chol is a ranking party official who is suspected of masterminding a number of attacks on South Korea.
"The issue of denuclearization of the Korean Peninsula can be resolved, if South Korea and the United States respond to our efforts with goodwill, create an atmosphere of peace and stability while taking progressive and synchronous measures for the realisation of peace," Kim Jong-un was quoted as saying by the Chinese Xinhua News Agency.
The "progressive and synchronous measures" are likely a reference to compromise on the part of Seoul and Washington, which the allies have ruled out without verifiable and irreversible denuclearization.
North Korea has long called for the cessation of joint South Korea-US military drills, saying that US military presence is detrimental to stability in the region and a direct threat to the regime. Pyongyang has also threatened retaliation against the US, claiming that international sanctions are an "act of war."
The efforts made by North Korea include offering to meet with South Korean and US leaders, and to halt nuclear and missile tests while related processes are underway.
Kim is set to meet President Moon Jae-in at the end of April, and US President Donald Trump sometime in May.
Regardless of the implications of Kim's comments, Cheong Wa Dae is taking the related developments as a positive sign ahead of the summits.
"Kim's comments from the summit (with Xi), such as that denuclearization is the will of his ancestors, signal positive effects for the inter-Korean and US-North Korea summits," a high-level Cheong Wa Dae official said on condition of anonymity.
He added that Cheong Wa Dae would elaborate on its position after Chinese State Councilor Yang Jiechi's visit to Seoul, and that the presidential office is handling North Korea-related issues with "all possibilities in mind."
According to Cheong Wa Dae, Yang will brief Seoul officials on the Kim-Xi meeting on Thursday when he visits as Xi's special representative. During his stay, Yang is to meet with Moon and his National Security Office chief Chung Eui-yong.
"During his visit (Yang) will provide a detailed account of the North Korea-China summit, and discuss current issues in South Korea-China relations including denuclearization of the peninsula," said Yoon Young-chan, Moon's chief press secretary.
Although Cheong Wa Dae remains tightlipped, the presidential office is said to have had information on the Kim-Xi meeting.
Beijing is said to have informed Seoul of Kim's visit at some point between Saturday and Tuesday.
Seoul's presidential office declined to pinpoint when it was informed of Kim's trip to China, saying only that Moon was briefed on the developments while in the United Arab Emirates. Moon was in the UAE from Saturday until Tuesday.
The White House also revealed that China notified the US of Kim's visit on Tuesday (US EST), According to White House press secretary Sarah Sanders, the Chinese government also relayed a personal message from Xi to Trump.