Beijing: For weeks Washington has pushed the view that Beijing is the key to solving the North Korean nuclear problem.

For days US President Donald Trump has publicly raised hopes that Chinese cooperation, after a successful meeting at Mar-a-Lago, is underway.

So why did China's foreign ministry spokesman snap on Monday: "China is not the culprit of the issue, nor does it hold the crux and the key to resolving it."

The United States was the most important participant, he said.