A draft of Cuba's new constitution omits the aim of building communism, although it keeps the Communist Party as the guiding force of the one-party system, as well as recognising private property and opening the door to gay marriage.

Cuba's national assembly in the capital, Havana, is debating this weekend a draft of the document to replace its current constitution, reflecting political, social and economic changes. 

Once lawmakers have approved the draft, it will be submitted to a popular consultation. The final document, which could include changes, will then be put to a national referendum.

The current draft omits a clause in the 1976 constitution on the ultimate aim of building a "communist society", instead simply focusing on socialism.

"This does not mean we are renouncing our ideas," Esteban Lazo, president of the National Assembly, was quoted as saying by state-run media.

Cuba had simply moved into a different era following the fall of the Soviet Union, he added.