North Korea and China announced Wednesday that Kim Jong-un and Xi Jinping had a summit two days ago. Kim visited Beijing at the invitation of Xi for a closed-door summit Monday.

As the specifics of their meeting are not yet known, its effect on the North Korean nuclear issue down the road is hard to predict, but there is a high possibility that it will complicate the matter of denuclearizing the North.

Through his first foreign trip since he took office in 2011, Kim seems to be seeking to mend long-frayed ties with China, North Korea’s key economic benefactor. Their ties could not get worse as Beijing joined the international community in imposing stiff sanctions on the North.

At the summit, Kim reportedly invited Xi to Pyongyang at his convenience and the Chinese leader accepted it.

There are few reasons to oppose their efforts to improve their ties. It can be viewed as a positive signal if they serve the goal of denuclearizing the North.

As the security situation related to the North’s nukes turned critical lately, with summits between South and North Korea and between the US and North Korea expected in April and May, respectively, Pyongyang and Beijing probably felt acutely the need to close ranks.

“It is our consistent stance to be committed to denuclearization on the peninsula, in accordance with the will of late founder Kim Il-sung and former leader Kim Jong-il,” Kim was quoted as saying by China’s Xinhua News Agency. This remark emphasizes the blood alliance of China and North Korea in the era of Kim’s father and grandfather.

The issue is what they might be seeking to achieve through their efforts to get closer.

There is a good chance that Xi and Kim may have discussed sanctions against the North. It is also likely that Kim asked Xi to work toward moderating them. One cannot exclude entirely the possibility that China, the North’s sole ally, will seek ways to accommodate the North’s demands.

If Kim’s overture for dialogue leads to China breaking from the international front of sanctions and China and the North getting back to the solid alliance of the past, the efforts to denuclearize North Korea will come to nothing.

Chinese State Councilor Yang Jiechi will visit Seoul on Thursday morning to brief South Korea on the results of Xi-Kim talks. China needs to be reminded of the importance of maintaining sanctions until the North’s complete, verifiable and irreversible denuclearization.

Beijing should know that the problem of North Korean nuclear armament will be further complicated if it seeks to use the issue as leverage for a hegemonic influence over the US on an array of issues including trade.

The US-led sanctions have begun to work in bringing Pyongyang to dialogue. Indisputably, China has played an indispensable role in sanctioning the North, which has eventually shown signs of change, such as an proposal for summits.

To Pyongyang, the prospect of gaining many concessions from the US through negotiations likely dimmed after Trump nominated hawkish figures such as CIA Director Mike Pompeo and former Ambassador to the UN John Bolton as secretary of state and national security adviser, respectively. This may have caused North Korea to turn to China as a “safety valve” in case its summit with the US goes awry.

It is hard to imagine a process of denuclearizing North Korea without China being involved. But if Beijing rushes to restore diplomatic, security and economic assistance to the North for the sake of their alliance or its regional hegemony, the process will likely go up in smoke. In this context, the Kim-Xi summit arouses concern of a confrontation between South Korea, the US and Japan on one side and North Korea, China and Russia on the other.

It will be beneficial to all countries concerned to avoid such confrontation, and China needs do more to persuade Pyongyang to scrap its nukes for peace on the peninsula.

Now is not the time to tamp down the dialogue momentum, but to hold fast to the principle of maximum sanctions until the North denuclearizes.