China suggested on Tuesday that sanctions relief could be considered for North Korea, after U.S. President Donald Trump and North Korean leader Kim Jong Un pledged to work toward complete denuclearization of the Korean peninsula.

China has signed up for increasingly tough U.N. sanctions against its isolated neighbor following Pyongyang’s repeated nuclear and missile tests, but has always said sanctions should be accompanied by talks for a political resolution.

China is North Korea’s most important economic and diplomatic backer, despite its anger at Pyongyang’s sabre rattling.

Speaking in Beijing following Trump and Kim’s signing of a joint statement at the end of their historic summit in Singapore, Chinese Foreign Ministry spokesman Geng Shuang reiterated that China has always strictly abided by all U.N. resolutions on North Korea.

“The U.N. Security Council resolutions that have been passed say that if North Korea respects and acts in accordance with the resolutions, then sanction measures can be adjusted, including to pause or remove the relevant sanctions,” Geng told a daily news briefing.

“China has consistently held that sanctions are not the goal in themselves. The Security Councils actions should support and conform to the efforts of current diplomatic talks towards denuclearising the Korean Peninsula, and promote a political solution for the peninsula.”

Beijing has key strategic interests when it comes to North Korea, and has long feared that a collapse of its isolated neighbour could push waves of refugees into northeastern China, or that nuclear war on the Korean peninsula could contaminate swathes of the country.

North Korea also serves as a valuable buffer state between China and U.S. forces in South Korea.

Speaking earlier in the day also in Beijing, the Chinese government’s top diplomat, State Councillor Wang Yi, said China hoped the United States and North Korea can reach agreement on a peace deal.

“We hope that the two countries’ highest leaders can dispel interference, establish mutual trust, overcome difficulties and can reach a basic consensus on promoting and achieving the denuclearization of the peninsula and promoting and establishing a peace mechanism for the peninsula,” Wang told reporters.

“Of course, we are willing to see all relevant sides making positive efforts on this. China will continue to play our constructive role,” he added.

China views the Korean Peninsula nuclear issue as a security issue, and what is most important is for the United States and North Korea to sit down to find a way to resolve their problems, Wang said.

“At the same time, there needs to be a peace mechanism for the peninsula, to resolve North Korea’s reasonable security concerns. I think nobody can doubt the extremely unique and important role China has played. And this role will continue.”

The 1950-53 Korean War ended with an armistice and a state of war still technically exists between the two Koreas.

Lasting peace has obvious benefits for China, especially in bolstering the development of its rust-belt and landlocked northeast which borders North Korea and would suffer in the event of conflict.