"Our weapons will remain in our hands until the Palestinian flag is hoisted in Jerusalem," Hamas leader Mahmud al-Zahar said at a rally in the centre of Gaza City on Tuesday to celebrate the Israeli pullout from Gaza.
"These weapons will remain with us so we can defend our land and citizens until the liberation is completed."
Hamas has been portraying the Israeli pullout as an act of surrender.
It is currently observing a truce agreed with Palestinian leader Mahmud Abbas but which has proved less than watertight.
Speaking against a backdrop of portraits of Hamas leaders assassinated by Israel, al-Zahar also warned that there could be no renunciation of the right of return for refugees who were forced from their homes when Israel was created.
"We swear that we will not renounce our rights over Haifa, Jaffa and Tel Aviv while our refugees in the diaspora cannot return to this land occupied by the Jews," he added, as thousands of supporters chanted Allahu Akbar (God is greatest).
"The right of return for refugees can never be sold off," added al-Zahar.
A Palestinian meanwhile died after being fatally wounded by Israeli fire outside the southern West Bank city of Hebron.
Walid Khamaisah, 19, had been shot in the stomach on Tuesday by soldiers in the village of Tafuh, west of Hebron, doctors at the city's Al-Ahli hospital said.
Five other Palestinians were also wounded when the troops fired rubber-coated bullets at stone-throwing demonstrators in the village, the medics said.
An Israeli army spokeswoman said the troops responded after one of their comrades was lightly wounded by the stone-throwers.