MIAMI (REUTERS) - Cuba's prize-winning blogger, Yoani Sanchez, is launching the island's first independent digital newspaper next week to challenge the communist-ruled country's state-controlled media.

Sanchez said the online publication will be named "14ymedio", in honour of the year of its launch and the 14th floor Havana apartment where she writes her popular Generation Y blog on daily life and politics in Cuba.

Going up against Cuba's heavy media restrictions will not be easy, she admitted in an announcement on her blog on Wednesday.

"It will be a difficult road. In recent weeks we have seen a preview of how official propaganda will demonise us for creating this medium," Sanchez wrote, adding that several of her online team have already received warning calls from Cuban state security officials prior to the official launch on May 21.

Public criticism of Cuba's communist system can be considered enemy propaganda, punishable by stiff jail sentences.

Sanchez, 38, has won several prestigious media awards in the United States and Europe and has been included on Time magazine's annual list of 100 most influential people.

Vowing to be totally independent and transparent, Sanchez said she opted for online journalism to voice her criticism of Cuba's one-party system, rather than becoming an opposition politician.

"A reporter should not have any kind of militancy," she said.

Instead, she hopes 14ymedio "will support and accompany the necessary transition that is going to take place in our country".