(CNN) US whistleblower Chelsea Manning has been refused a visa to enter Australia where she was due to make a series of public appearances, her touring company announced Thursday.

The company, Think Inc., said in a statement it had been notified of the Department of Home Affairs' decision on Wednesday and would be appealing it.

"Think Inc. believes Ms. Manning is entitled to freedom of expression and political opinion which are foundations of a free and democratic society and fundamental human rights," the organization's official statement said.

Her first public engagement was due to be held at the Sydney Opera House on Sunday, her touring company said, before appearances in Melbourne and Brisbane.

Chelsea Manning attends an OUT Magazine event at the Altman Building in New York on November 9, 2017.

Manning was convicted in 2013 of stealing 750,000 pages of sensitive government documents and videos and leaking them to WikiLeaks. She was sentenced to 35 years in prison, but had her sentence commuted by then-President Barack Obama in January 2017.

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