Diplomatic niceties for Trump in Beijing

President Donald Trump nodded appreciatively as China’s Xi Jinping showcased a centuries-old temple in Beijing’s Forbidden City. He clapped along as the two leaders watched a Chinese children’s opera. And the pair shared a traditional tea and salutations of friendship.

Trump’s two-day visit to China opened with diplomatic niceties aplenty Wednesday. But thorny issues await the two world leaders behind closed doors, including potential tensions over trade and China’s willingness to put the squeeze on North Korea over its nuclear weapons program.

Ahead of his arrival, Trump delivered a stern message to Beijing, using an address to the National Assembly in South Korea to call on nations to confront the North.

“All responsible nations must join forces to isolate the brutal regime of North Korea,” Trump said. “You cannot support, you cannot supply, you cannot accept.”

He called on “every nation, including China and Russia,” to fully implement U.N. Security Council resolutions against North Korea enforcing sanctions aimed at depriving its government of revenue for its nuclear and ballistic missile programs. The latest measure, adopted after a September atomic test explosion, the North’s largest yet, banned imports of its textiles and prohibited new work permits for overseas North Korean laborers. It also restricted exports of some petroleum products.