China appears to be facing a tough strategic decision over how to handle North Korea, amid growing U.S. pressure to tame its wayward ally that has hinted at the possibilities of a long-range rocket launch and another nuclear test.

In response to the continuing calls from Washington to play the role of a “responsible stakeholder” in regional security, Beijing has been agonizing over ways to curb Pyongyang’s nuclear ambitions and provocative acts.

But solutions to the issues remain elusive, as the North is adamant about its development of nuclear weapons capabilities, which analysts say could undermine regional stability, a prime goal of China’s foreign policy.

The North’s nuclear issue is likely to be high on the agenda for the summit between U.S. President Barack Obama and his Chinese counterpart Xi Jinping, slated for Friday. The two leaders are expected to put up a united front against the North’s nuclear development, according to U.S. National Security Advisor Susan Rice.

The summit is expected to be yet another case that underscores Beijing’s policy challenge regarding the unpredictable regime, experts noted.

“In a broad context, China basically seeks regional stability. To this end, China feels the need to embrace the North to a certain degree, but there is no shift at all in Pyongyang’s stance about its nuclear program, which apparently gives China a headache,” Chang Yong-seok, a senior analyst at Seoul National University’s Institute for Peace and Unification.

“So, China can hardly fend off the U.S. calls to further pressure the North. It cannot move in support of the North, either.”

As the close ties between Seoul and Beijing have been highlighted in recent years, speculation has grown that both Beijing and Pyongyang will make moves to restore bilateral relations. But there has yet to be any clear sign of the two neighbors seeking to mend their rifts.

President Park Geun-hye and Xi have met for summit talks six times, underscoring the evolving strategic partnership between the two nations, which has triggered concerns about a possible chasm in the South Korea-U.S. alliance.

But there has not been a summit between Xi and North Korean leader Kim Jong-un, an indication that the bilateral political trust has been eroding due to the North’s destabilizing behavior. Despite China’s opposition, the North has engaged in a series of provocative acts, including the third nuclear test in February 2013.

Chun In-young, professor emeritus at Seoul National University, stressed the need for Pyongyang to move first to restore ties with Beijing, saying that Pyongyang’s adherence to its nuclear adventurism demonstrates its failure to adapt to the new regional security environment where China has emerged as a great power.

“Those days when China served as a guardian for the North are gone. China, now a critical factor in the international order, would no longer take the side of the North, as evidenced by the recent move to join the U.S. in the efforts to oppose the North’s nuclear program,” he said.

“During the Cold War, particularly when China and the Soviet Union were in a conflict, the North held some leverage. But those days are gone. Pyongyang insisting on its nuclear ambitions is failing to adapt to the new security environment.”

By Song Sang-ho(sshluck@heraldcorp.com)