SEOUL -- The presidents of South Korea and China agreed on Monday to cooperate to defuse tensions on the Korean Peninsula, as Pyongyang threatens provocations ahead of its self-imposed year-end deadline for sanctions relief.

South Korean President Moon Jae-in had lunch with his Chinese counterpart, Xi Jinping, in Beijing on a stopover in the Chinese capital. Moon will travel to the southern Chinese city of Chengdu later Monday for a trilateral summit with Chinese Premier Li Keqiang and Japanese Prime Minister Shinzo Abe on Tuesday.

"It is never good for North Korea, as well as for other countries, that the North-U. S. talks stop and tensions rise on the Korean Peninsula," Moon said in his opening remarks. "I hope that we can cooperate more closely to make this rare chance [to lessen tension] a reality."

Xi said China and South Korea should pursue peace and prosperity in the region. "We agree on many things, such as improving our bilateral relations and promoting peace, security and prosperity in the region. We also defend multilateralism and free trade," he said.

The meeting comes one day after North Korea's state media reported that leader Kim Jong Un hosted a high-level military meeting. Pyongyang has set a year-end deadline for the U.S. to come up with an offer to ease sanctions, warning that it will send a "Christmas gift" to Washington if it does not.

Leif-Eric Easley, associate professor of international studies at Ewha Womans University in Seoul, said North Korea will calibrate any military provocations so they do not offend China.

"Pyongyang can instead seek headlines with a high-level Workers Party meeting ahead of Kim's New Year announcements," Easley said. "So we can expect more rhetoric and preparation before a major launch."

Xi and Moon reaffirmed the friendship between their two countries, although Moon acknowledged that relations have soured in recent years. Xi said that South Korea is China's friend and partner, while Moon mentioned that they share long history and culture.

Moon also mentioned that China and South Korea can also cooperate in third countries on the Belt and Road Initiative, Xi's drive to connect Asia and Europe. South Korea has new Southern and Northern policies aimed at strengthening Seoul's ties with Southeast and Central Asian countries.