The document notably accepts the idea of a Palestinian state in territories occupied by Israel in the Six-Day War of 1967.
It also says its struggle is not against Jews because of their religion but against Israel as an occupier.
However, Hamas officials said the document in no way amounts to recognition of Israel as demanded by the international community.
"...Hamas considers the establishment of a fully sovereign and independent Palestinian state, with Jerusalem as its capital along the lines of the 4th of June 1967, with the return of the refugees and the displaced to their homes from which they were expelled, to be a formula of national consensus," it says.
The movement's leaders have long spoken of the more limited aim of a Palestinian state in the West Bank and the Gaza Strip without explicitly setting it out in its charter.
But after years of internal debate, the new document formally accepts the idea of a state in the territories occupied by Israel in the Six-Day War of 1967.
Hamas, which controls the Gaza Strip, remains deeply divided from Fatah, the more moderate party of Palestinian president Mahmud Abbas based in the occupied West Bank.
Hamas's announcement comes ahead of Abbas's first face-to-face meeting with US President Donald Trump in Washington on Wednesday.
The new document was posted online as exiled Hamas leader Khaled Meshaal was due to hold a press conference on it in Doha.
The press conference was also being broadcast live in the Gaza Strip.
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