"We will do everything we can to support her in this difficult time." Lee himself toes a delicate line on the mainland.
Though based in the United States, he is a Taiwan citizen, which in the eyes of Beijing makes him officially "one of theirs".
An order also went out banning any promotion of the actress, and newspaper websites were told to remove stories mentioning her.
Websites also took down discussions of the ban, while attempts to search for her name on Google News were also blocked.
China makes dozens of propaganda films every year, but most of them fail to make a ripple beyond China's borders, and are met with indifference by the broader audience even within China.
But The Founding of a Republic transformed the Chinese propaganda movie in that it was of higher quality than the usual fare.
In the tv version – our female lead becomes a mellower princess protected by at least three men in her life, but in the book, she’s strong, scheming, cunning, and eventually rises to the position of an Empress.
The past few years have been a rollercoaster ride for Ms Tang, who was purged in 2007 for her erotic role as the lover of a collaborator in Japanese-occupied Shanghai in Lust, Caution.
Tang Wei, who played a young war-time revolutionary in Lust, Caution, has suddenly disappeared from television screens and the media in China, despite having become one of the country's hottest celebrities.
"I am very disappointed that Tang Wei is being hurt by this decision," Lee said in a statement.
The film also features some of Hong Kong's top actors.
Andy Lau stars as the warlord and revolutionary Cai E and Chow Yun-fat as Yuan Shikai.