BEIJING — For years, the United States and others have pressed China’s leaders to suspend imports of coal from North Korea to push the reclusive state to abandon its nuclear weapons program. For years, the Chinese leadership resisted — until Saturday, when it suddenly announced in a terse statement that it would do just that.

But if Beijing was sending a message to North Korea, it was also directing one at President Trump, who has complained that China was not putting enough pressure on North Korea.

Now President Xi Jinping of China has essentially said: We have done our part in enforcing sanctions. Over to you, Mr. Trump.

The challenge comes at a tantalizing moment. For weeks now, plans have been afoot for a North Korean government delegation to meet in New York in early March with a group of former United States officials who have long been involved in North Korea policy.