BEIJING – After months of strained relations and provocations, North Korea sent signals this week that it wants to re-engage with its longtime ally China and possibly resume international negotiations on ending its nuclear weapons program.

On Friday, a high-level North Korean envoy delivered a letter from North Korea’s leader, Kim Jong Un, to Chinese President Xi Jinping, ending an unusually long period of schism between the two countries.

Xi responded after the meeting by forcefully urging North Korea to resume dialogue with other countries, according to the state-owned China News Service. “China has a very clear position: that all the concerned parties should keep to the goal of denuclearization, safeguarding peace and stability on the peninsula, and resolving disputes through dialogue and consultation,” Xi said.

And according to Chinese media, the envoy, Vice Marshal Choe Ryong-hae, has said at least twice during his three-day visit that North Korea is “willing to accept the suggestion of the Chinese side and launch dialogue with all relevant parties.”

The contents of Kim’s letter to Xi were not revealed by authorities and state news media from either country. But early Saturday, North Korea’s state news agency said Choe had told Xi during their meeting that the two countries’ alliance “cannot be exchanged for anything.”

Beijing has shown increasing signs of frustration with North Korea, after it ignored pleas not to carry out a nuclear test.