China hosted the leaders of squabbling neighbors South Korea and Japan for their first official meeting in over a year Tuesday, flexing its diplomatic muscle with America’s two key Asian allies and seeking unity on how to deal with a belligerent North Korea.

The gathering in Chengdu was held with the clock ticking on a threatened “Christmas gift” from North Korean leader Kim Jong Un that could re-ignite global tensions over its nuclear program.

Kim has promised the unidentified “gift” — which analysts and U.S. officials believe could be a provocative missile test — if Washington does not make concessions in their nuclear talks by the end of the year.

U.S. President Donald Trump said Tuesday that “we’ll find out what the surprise is and we’ll deal with it very successfully,” joking that “maybe it’s a present where he sends me a beautiful vase as opposed to a missile test.”

The Tuesday gathering in China featured the first bilateral meeting between South Korea’s Moon Jae-in and Prime Minister Shinzo Abe in 15 months.

Ties between the two Asian leaders have hit rock bottom lately over trade issues and other disputes related to decades of bitter wrangling over Japan’s 1910-1945 colonial rule of the Korean Peninsula.

The United States has urged the pair to bury the hatchet — worried their poor relations were complicating diplomacy in Asia — although it has held off on direct mediation.

China appeared to fill that void during the annual meeting.

“As the region’s major power, China hopes to show its diplomatic presence to the world by bringing the Japanese and South Korean leaders to the same table,” said Haruko Satoh, professor and expert on Chinese politics at Osaka University.

Before leaving for China, Abe told reporters that relations with Seoul remained “severe.”

But Abe and Moon were photographed smiling and shaking hands, and made positive overtures at the start of their bilateral meeting.

Ties between Japan and South Korea began a downward spiral in recent months after a series of South Korean court rulings ordering Japanese firms to compensate wartime forced labor victims.

These infuriated Tokyo, who insisted the matter had been settled by a 1965 treaty between the two countries.

Seoul then threatened to withdraw from a key military intelligence-sharing pact, although it reversed course in November and agreed to extend it “conditionally.”

Abe said he hoped “to improve the important Japan-South Korea relations and to exchange candid opinions,” according to NHK.

On Tuesday, Seoul’s presidential Blue House said Moon described the two countries as “the closest neighbors geographically, historically and culturally.”

But at a news conference after the bilateral, Abe said it was “South Korea’s responsibility” to resolve the issues.

“I urge the South Korean side to get the ball rolling to regain the soundness of Japan-South Korea relations,” he said.

After the meeting with China, both Japan and South Korea urged the resumption of talks between Pyongyang and Washington — which have been largely deadlocked since a second summit between Trump and Kim in Hanoi collapsed at the start of this year.

The leaders of the three countries also promised to help promote dialogue to rid the Korean Peninsula of nuclear weapons.

Also on Tuesday, North Korean state media slammed Tokyo as a “political dwarf,” saying its weapons tests “pose no threat” to Japan.

Still, if the North fired an intercontinental ballistic missile in defiance of U.N. sanctions, it would destroy Trump’s argument that he had succeeded in reducing risks from North Korea.

Former U.S. national security adviser John Bolton, who was dismissed in September, on Monday criticized Trump’s strategy and warned the North posed an immediate threat.

“The risk to U.S. forces & our allies is imminent & more effective policy is required before NK has the technology to threaten the American homeland,” Bolton tweeted.