China faces a strategic dilemma as South Korea and the U.S. remain steadfast despite North Korea’s peace offensive, while its balky ally covertly continues to ramp up its nuclear capability, extending the standoff and imperiling regional stability.

Beijing has long defended Pyongyang against international sanctions using its veto power in the U.N. Security Council and provided economic assistance crucial for its survival.

As tensions escalated on the peninsula this year, however, Chinese President Xi Jinping has been pressing the Kim Jong-un regime harder to cease provocations and drop his nuclear ambitions.

On Thursday, Xi and South Korean President Park Geun-hye agreed in their talks in Beijing to make efforts for the denuclearization of the peninsula. They said North Korea’s development of nuclear weapons poses a “grave threat” to peace and stability in the region and the world.

“The two sides affirmed that the realization of denuclearization on the Korean Peninsula, and the maintenance of peace and stability on the Korean Peninsula are in accordance with common interests, and agreed to work together for this,” the joint statement said.  

But the communiqué failed to carry significant measures to rid North Korea of its atomic devices or address the strategic instability stemming from them. It merely carried a pledge to “reinforce various forms of bilateral and multilateral dialogue within the six-party talks to realize the denuclearization of the peninsula.”

At an earlier meeting with U.S. President Barack Obama, Xi reaffirmed that he would not accept the North as a nuclear state. Kim’s envoy Choe Ryong-hae requested the recognition during his recent trip to Beijing but the Chinese leader apparently brushed it off.

Although Obama and Xi aligned their stance, China was unable to change the U.S. condition that Pyongyang must first demonstrate its sincerity by carrying out its commitments enshrined in the Sept. 19, 2005, six-party agreement, said Peter Hayes, executive director of the California-based Nautilus Institute and a professor at RMIT University in Australia.

North Korean nuclear negotiator Kim Kye-gwan’s visit to Beijing last week was “to simply compare notes about American obduracy, and to tell China: ‘We told you so,’” he wrote in a recent analysis.

Beijing’s patience appears to have been thinning since Pyongyang in February snubbed repeated warnings against a third atomic test, following a successful launch of a long-range missile in December.

It further ratcheted up tension with a weeks-long blizzard of threats of nuclear strikes on South Korean and U.S. territory.

In a sign of fury, Beijing joined Washington in March in imposing the U.N.’s toughest sanctions over the underground blast, while afterward reportedly tightening inspections of cargo shipped to and from its reclusive neighbor.

Then in May it halted transactions with the Foreign Trade Bank, which was accused by the U.S. Treasury Department of being a “key financial node in North Korea’s weapons of mass destruction apparatus.”

China this week also gave the green light to a plan to expand a U.N. sanctions committee on North Korea and release the panel’s new blacklist of North Korean individuals and entities subject to sanctions.

Apparently caving to pressure, Pyongyang proposed a high-level governmental meeting with Seoul and then Washington this month.

“China is angered by the nuclear test and has deep frustration. China is feeling deeply humiliated by the fact that North Korea had rejected its persuasion to the end,” Kim Sook, South Korea’s ambassador to the U.N., told reporters shortly after the latest sanctions’ approval.

But the series of unusual moves need not represent a sweeping shift in Beijing’s approach to North Korea, analysts say.

With stability being its top concern in the region, China has been calling for the resumption of the six-party talks involving the U.S., Japan, Russia and the two Koreas.

China’s commitment to the denuclearization of the peninsula reflects its concerns that a nuclear-armed North Korea would prompt the U.S., Japan and other rivals to boost their own military might and thus undermine its national interests.

Xi’s nascent leadership is also grappling with a slew of domestic hurdles such as political reform, a cooling economy and growing public calls against its long-standing patronage of a rogue neighbor.

“China is not in a situation to abandon North Korea especially given its recent diplomatic offensive,” said Yoo Ho-yeol, a North Korea studies professor at Korea University in Seoul.

“During the South Korea-China summit, Xi would inevitably imprint the historic nature of the relationship with North Korea rather than unilaterally decry it.”

Despite the North’s ongoing attempts at rapprochement, Beijing’s conundrum is showing no sign of easing.

What would have been the first cross-border dialogue in years soon fell apart following disputes over lead delegates. Washington responded with demands that Pyongyang prove sincerity with preemptive steps toward denuclearization.

Cho Tae-yong, Seoul’s special representative for Korean Peninsula peace and security affairs and top nuclear negotiator, called for “stronger obligations” on the North before any restart of talks than those stipulated in its defunct agreement with the U.S. on Feb. 29, 2012.

Under the so-called Leap Day Deal, Pyongyang agreed to put a moratorium on its nuclear enrichment program, stop atomic and missile tests and let in IAEA inspectors in exchange for 240,000 tons of food aid.

“It is urgent that the North give up its nuclear program and that credible dialogue take place,” Park said in an interview with the state-run China Daily ahead of the summit.

North Korea, in contrast, codified its nuclear status last year. It said early this year that nuclear development was one of the top national priorities and, thus, no longer up for bargaining.

While calling denuclearization a “behest” of its two late autocrats, the communist state said it will not relinquish its atomic programs unless the U.S. withdraws its “hostile” policy including dissolution of the U.N. Command here.

Satellite images indicated signs of new tunnel work at its nuclear test site in the country’s northeast, but another detonation, though, did not appear imminent, the U.S.-Korea Institute at Johns Hopkins School of Advanced International Studies said Tuesday.

“The timing of North Korea’s proposal to resume direct talks with the U.S. appears primarily designed to discern fissures in the converging positions of the U.S., China and South Korea on North Korea’s denuclearization,” Scott Snyder, director of the program on U.S.-Korea policy at the Council on Foreign Relations, wrote in an analysis.

“The North Korean proposal tests Sino-U.S. relations since the U.S. has conveyed that North Korea must take concrete actions to show its sincerity as a precondition for the resumption of nuclear talks, while China has emphasized the importance of returning to dialogue even while affirming it will not accept a nuclear North Korea.”

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