Bookended by hopeful words of mutual understanding and improved relations, China’s top diplomat in the US delivered a tough message on Thursday in New York: Do not mess with China and do not seek regime change.

The presentation by Xie Feng, China’s ambassador to the United States, celebrated the 45th anniversary of normalised relations, people-to-people ties, explosive bilateral trade growth and past examples of cooperation. But interspersed with the feel-good outreach was his strongly delivered main message.

“Pressure, sanctions, isolation, containment and blockades don’t serve the purpose,” said Xie. “Rather, they bring self-inflicted trouble and require extra work to offset the unwanted results.”

He proceeded to outline in no uncertain terms four “red lines” in US-China relations: Taiwan, democracy, human rights and China’s freedom to develop.

“China will not repeat the historical pattern where powerful nations seek dominance,” he said in a video address to a conference at New York’s Asia Society. “The Taiwan question is the most paramount in China-US relations and must not be crossed. The notion of democracy versus authoritarianism is a fallacy. China’s political system and development path are non-negotiable.