The Chinese Ambassador to the US, Cui Tiankai, issued a reminder to incoming U.S. President Donald Trump about what makes China-U.S. relations work.

More than a week ago, Trump took a phone call from the leader of Taiwan, and over the weekend, he suggested the U.S. was not bound by the One-China policy.

Since then Beijing has issued a series of stern warnings but none have come in a public setting in Washington D.C., until now.

A little more than 24 hours before he was to accept an award from the U.S. China Business Council, the council got word that the embassy wanted to open his remarks to the media.

In his 10-minute remarks, Cui linked the forces of protectionism and anti-globalization to the U.S. presidential election results and issued this reminder.

“Basic norms of international relations should be observed, not ignored. Certainly not something you can trade off. Indeed, national sovereignty and territorial integrity are not bargaining chips. Absolutely not,” said Cui.

The Chinese Ambassador to the U.S. called on the business community to help maintain relations between the world’s two largest economies.