North Korea’s third nuclear test is expected to further erode China’s patience toward the runaway ally as Beijing comes under mounting pressure to join international action against the communist country’s blunt provocations.

China strongly criticized the Tuesday blast, warning against “additional actions that could cause the situation to further deteriorate.”

“Heedless of widespread international opposition, (North Korea) has again carried out a nuclear test, to which the Chinese government expresses its firm opposition,” Beijing’s Foreign Ministry said in a statement.

When the high-stake detonation appeared imminent, Beijing was seen pulling out the stops to convince its rogue ally to change tack while threatening to cut off economic assistance vital to its survival.

Though the North is believed to have informed China of its plan a day before, Pyongyang’s increasing unruliness and habitual provocations have become a road block in China’s path to becoming a responsible world leader.

With stability being top priority, however, president-in-waiting Xi Jinping will sustain patronage to maintain its influence over the North and keep it as a pivotal buffer against rising U.S. influence in the region, experts say.

They pointed to more nettlesome challenges facing the incoming leadership at home, from rampant inequality to slowing growth, to rising middle-class demand for political reform.

“The nuclear test is not likely to change China’s attitude,” said Chin Hee-gwan, a unification studies professor at Inje University in Gimhae, South Gyeongsang Province.

“It may run counter to China’s intentions but does not constitute a sharp difference from a strategic point of view.”

In the wake of Tuesday’s nuclear test, Seoul, Washington and other partners vowed additional, more stifling measures in line with Resolution 2087, possibly targeting the North’s financial assets or sea transport.

While China is unlikely to forsake the blood alliance, the regime’s defiance will leave no other option for China but to cave into pressure to impose further bans, Chin said.

In the statement, China again shied away from joining international condemnation, repeating its long-standing focus on peace, stability and the resumption of denuclearization talks.

China has for decades been propping up Pyongyang by supplying food, fuel and other necessities, and providing political backing in the face of international censure.

Beijing’s role has gained particular traction after the U.N. Security Council on Jan. 22 approved stronger-than-expected sanctions as punishment for the North’s December rocket liftoff.

Its endorsement marks a shift away from its normally rigid resistance to any compulsory measures against Pyongyang, triggering a rift between the two allies.

One day after the approval, the North’s National Defense Commission blasted China for “abandoning without hesitation even elementary principles under the influence of the U.S., using arbitrary and high-handed practices and failing to come to their senses.”

Last week, the Choson Sinbo, a Tokyo-based mouthpiece for the North Korean regime, again criticized its big brother for being unable to correct “wrongful acts” by the U.S. and “conniving at intrusions on a certain country’s sovereignty.” Without explicitly naming China, the newspaper referred to a “big country” whose “rapid economic growth elevated its international standing.”

China, for its part, shot back by calling for a cut in assistance in response to another atomic explosion in an editorial carried by state-run Global Times on Jan. 25.

The country’s customs agency has reportedly tightened inspections of cargo shipped to and from North Korea through main routes along the border.

Other news reports said that Beijing’s Foreign Ministry had repeatedly called in North Korean Ambassador Ji Jae-ryong and other officials since the regime on Jan. 24 threatened to conduct more missile and nuclear tests.

While many doubt any stark turnaround in China’s North Korea policy or their “blood” relationship, the recent war of nerves prompted optimistic views about future global cooperation in taming Pyongyang’s nuclear ambitions.

“If China sees North Korea’s test as evidence of political infighting in North Korea, it is less likely to change its current policy approach toward the North out of fear that tougher international sanctions might lead to North Korea’s destabilization,” Scott Snyder, a senior fellow for Korea studies at the Council on Foreign Relations, wrote recently.

“On the other hand, if China sees North Korea’s test as evidence of North Korea’s political consolidation but in a direction contrary to Chinese interests, there is a higher possibility that China might align itself more closely with the international community and against North Korea in the aftermath of a North Korean test.”

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