President Park Geun-hye and her Chinese counterpart Xi Jinping displayed their commitment to an “outright, full” enforcement of the latest U.N. sanctions on North Korea, during their first meeting on Thursday in Washington since Pyongyang’s fourth nuclear test.

The two presidents’ seventh one-on-one talk came as part of Park’s relay meetings with leaders of the U.S., Japan and other countries on the sidelines of the Nuclear Security Summit, focusing on consolidating a united front against the North’s evolving nuclear threats.

Park’s reunion with Xi boosted hopes for furthering the bilateral relationship that has been put to the test in the past couple of months as the sides spar over plans to deploy U.S. missile defense assets in South Korea amid Beijing’s calls for peace treaty talks with Pyongyang.

During the 80-minute gathering, Park expressed gratitude over Beijing’s work as a permanent member of the U.N. Security Council which passed strictest-ever sanctions against the defiant Kim Jong-un regime early last month.

With the young ruler threatening further nuclear tests and strikes on Seoul, Park was also expected to appeal to Beijing to play a more active role in tackling nuclear issues and forestalling further provocations.

Xi said he was hoping that South Korea and China would deepen two-way exchanges and cooperation and “pursue a sound, smooth development” of ties.

“North Korea’s recent nuclear test and missile launch provocations once again wakened the importance of the two nations’ cooperation in securing peace and stability, not only on the peninsula, but in the region,” Park said at the outset of the talks.

The mood appeared cordial as Park walked into the meeting room and shook hands with Xi, who had been waiting, followed by a trade of broad smiles. 

The two leaders have boasted personal rapport through various occasions since they each took office, adding to diplomatic and economic relations.

But tension was sparked as China openly criticized the envisioned stationing of the Terminal High Altitude Area Defense system here and warned of an impact on bilateral relations. Park also harbored “disappointment” after Beijing had for almost one month not responded to Cheong Wa Dae’s request of a phone conversation between the leaders over the Jan. 6 underground blast, diplomatic sources say.

Despite a recent clash of nerves and persistent sources of contention, the meeting may help instill fresh vigor into governmental and executive ties, some officials and experts say.

“For the North, the summit itself would convey tremendous pressure. I see there have been signs of a change in China’s attitude toward the nuclear issue and its relations with Pyongyang per se, since its latest atomic and missile experiments, though what kind of decision, if any, the change would lead to remains to be seen,” a Foreign Ministry official said, requesting anonymity due to the sensitivity of the matter.

“Looking at past patterns, China usually wouldn’t be expected to have a one-to-one summit with South Korea, not to mention a phone call, right after North Korean provocations.”

Another senior diplomat echoed the official’s view. “I have yet to speak with those in Beijing, but I can sense a subtle change in their approach. I don’t think their peace treaty talks offer, as well as the U.S.’ not-too-negative response, means more than a gesture to appease Pyongyang and dissuade it from staging another provocation, because they can’t just shut the door for dialogue while slapping sanctions and intensifying pressure.”

The Sino-North Korea relationship appears to be undergoing a “transitional recalibration,” say Chung Jae-heung and Lee Seong-hyon, researchers at the Sejong Institute. They were referring to Beijing’s tighter enforcement of sanctions, curtailed border trade and other punitive steps.

Official remarks from China also portrayed the change, for example, Foreign Minister Wang Yi who during last month’s news conference described the relationship as a “nation-to-nation” one, not a “blood-forged alliance,” and pledged “not to be dragged around” by its recalcitrant neighbor.

“The latest nuclear and missile tests triggered calls inside China for stern sanctions, and the perception of North Korea as a liability rather than an asset,” they wrote in a report released Wednesday.

“More young scholars and experts are looking at the North Korea issue from the aspect of major country diplomacy, and starting to perceive the entire Korean peninsula -- not just the North -- as a buffer zone, thus stressing the need to normalize ties with Pyongyang and reinforce relations with Seoul.” 

But Chang Yong-seok, a senior researcher at the Institute for Peace and Unification Studies at Seoul National University, cautioned against South Korea pushing too hard for China’s tighter squeeze, saying it may backfire and drive away sufficient cooperation.

“China will likely implement the resolution more painstakingly than before, but sanctions are not its end goal and it also firmly rejects unilateral sanctions that could dent its national interests and impact businesses,” he said.

“While levying sanctions is inevitable and we should keep watching what China will do about it, the limits of sanctions are clear. Seoul shouldn’t go forward too fast, talking about a ‘regime change,’ given the indispensableness of the collaboration with neighbors.”

At Xi’s separate meeting with U.S. President Barack Obama, the presidents reaffirmed their commitment to a nuclear-free peninsula and full implementation of the UNSC resolution, and vowed to enhance communication and coordination on the nuclear issues, according to the White House.

But they again showed a gap in views over the THAAD battery dispatch to South Korea and territorial rows in the South China Sea.

Xi said the country is “firmly opposed” to the deployment plan which would “undermine China’s security interests” and the regional strategic balance, Beijing’s assistant foreign minister Zheng Zeguang said in a news briefing in Washington.

Xi was also expected to have delivered a similar message to Park. When asked about the issue, Cheong Wa Dae’s senior presidential secretary on foreign policy and security Kim Kyou-hyun simply said that the sides swapped their existing stances and agreed to continue communication.

Earlier in the day, Park held separate meetings with Obama and Japanese Prime Minister Shinzo Abe. At a trilateral session between the three countries, they vowed to step up security cooperation to “deter and defend” North Korean provocations, while increasing efforts to promote “vigilant” enforcement of the UNSC and their individual measures as well as to improve human rights in the communist state.

The three leaders explored ways to “shift North Korea’s strategic calculations,” Park said in a press statement, warning that the regime will “not be able to survive without abandoning nuclear weapons.”

They also reportedly reached a consensus on carrying out consultations over greater tripartite security collaboration involving an early adoption of a formal intelligence-sharing accord between Seoul and Tokyo.

In 2012, South Korea pulled out at the last minute from a signing ceremony with Japan for the bilateral General Security of Military Information Agreement, which will facilitate exchange of North Korea-related information and search-and-rescue-related operations. The move came amid vehement public and political criticism over clandestine negotiations. With Washington serving as a mediator, an “arrangement” was made in December 2014. 

But the position of Seoul’s Defense Ministry remains “unchanged” that this may be realized only when the necessary environment is created, spokesman Moon Sang-gyun told reporters on Friday, referring to lingering skepticism toward a military partnership with the former occupier.

By Shin Hyon-hee (heeshin@heraldcorp.com)