Tweets from Chinese diplomats abroad, including seasoned Ambassador to the United States Cui Tiankai, have opened a fresh front in Beijing's increasingly assertive approach to diplomacy and propaganda and may be a sign of things to come.

Cui sent his first tweets just last week from his newly opened Twitter account, including one about Taiwan, the self-ruled and democratic island China claims as its own, garnering thousands of comments.

"#Taiwan is part of #China. No attempts to split China will ever succeed. Those who play with fire will only get themselves burned. Period," Cui tweeted, after China threatened sanctions on U.S. firms selling weapons to Taiwan.