North Korean leader Kim Jong-un has sent a “congratulatory letter” and “a floral basket” to the Chinese president Xi Jinping, the official Korea Central News Agency (KCNA) reported on June 16.

There seems to be no special occasion for the congratulation — other than that it came a few days after Kim’s meeting with US President Donald Trump in Singapore.

Kim arrived in Singapore and was flown back to Pyongyang in an Air China jet. China’s behind-the-scenes role in the Singapore summit should not be estimated, political observers in the region suggest. In fact, China may be the main player in the game as it shares a border with North Korea and is eager to see sanctions, which it has pledged to accept, lifted.

Apart from a potentially lucrative cross-border trade, China has also strategic interests in the Korean peninsula, which includes being wary of US military presence in South Korea.

Trump’s decision to halt, at least temporarily, joint US-South Korean military exercises — which the US president called “war games” — must have been welcome in Beijing, the sources suggest. The suspension of those games has long been requested by Pyongyang, a view the North Koreans quietly share with the Chinese.

But the decision may cause concern in South Korea — and driving a wedge between South Korea and the US is also in China’s interest. Kim said in his congratulatory message to Xi that he “highly appreciated the successive meetings” with the Chinese president.

Xi, Kim said, has “made positive contributions to the international prestige of China and preserving global peace and security.” Kim, who assumed power in 2011, did not visit China until March this year and paid a second visit to China in May as he was preparing for his meeting with Trump.

Kim’s meetings with Xi have deepened “the special comradely friendship and trust” between North Korea and China, and promoted “the strategic choice made by the two parties and the two countries, as required by the new era, KCNA reported.