South Korean Foreign Minister Yun Byung-se said Wednesday that should Pyongyang press ahead with its fourth nuclear test, it would be a “direct challenge” to China.

During a press conference in New York, Yun noted that Beijing has made a flurry of efforts to discourage its wayward ally from conducting another test, which would substantially enhance the North’s nuclear capability.

Yun was in New York to lead U.N. activities as South Korea holds a one-month presidency at the U.N. Security Council this month.

Underscoring that China maintains a “tough, principled” stance regarding the North’s nuclear provocation, Yun said that China would join much stronger sanctions that might be adopted should the North carry out another test.

But China could take a different stance as to the form of sanctions given that it regards stability in the impoverished state as an important issue in addition to the North’s denuclearization, the minister pointed out.

Citing their analysis of satellite images, media reports have said that Pyongyang is preparing for a nuclear test, with some claiming that another test was imminent, given the final preparation phase at the test site in the northeastern town of Punggye.

Amid Pyongyang’s stepped-up push for nuclear development, international pressure has been increasing on Beijing to exert more influence to persuade the North to renounce its nuclear ambitions.

Unlike in the past, Beijing has shown an increasingly tough stance toward the North’s nuclear program as the program could destabilize the region and prompt Seoul and Tokyo to consider their own nuclear armament, observers said.

In an apparent indication of his discomfort with the unpredictable North Korean regime, Chinese leader Xi Jinping has yet to meet North Korean leader Kim Jong-un, who took power more than two years ago. Xi has met South Korean President Park Geun-hye four times so far.

Regarding when the North would carry out its nuclear test, Yun said, “It is hard to predict.” But he stressed that the international community shared the view that Pyongyang would face heavier sanctions for another test.

In a UNSC debate, Yun called for the council’s concerted efforts to prevent the North’s nuclear test, defining Pyongyang’s nuclear program as a “clear and present” threat.

“Should North Korea succeed in acquiring nuclear weapons, this would seriously damage the Nuclear Non-Proliferation Treaty system and exacerbate tensions in Northeast Asia,” said Yun.

“If (we) fail to effectively deal with the clear and present threat (from the North), this would weaken not only the credibility of the UNSC, but also the basic spirit of the U.N. Charter.”

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