According to Hamas' website, Mashaal made the statements during a visit to Doha, the capital of Qatar. He noted that the deal is currently in a very important and delicate stage.
He also accused Israel of trying to "manipulate and play games" as well as other elements of trying to hinder it. Mashaal noted that "Hamas continues to stick to its demands."
Mashaal's message contradicts the statements made by his deputy Moussa Abu Marzouk as quoted Sunday by the London-based al-Hayat newspaper.
According to the paper, Marzouk estimated that Hamas would receive Israel's official response via the German mediator Gerhard Conrad in respect to the organization's demands within two days.
Abu Marzouk accused Conrad of not acting "more resolutely in order to achieve a compromise between the sides."
He further noted, "Currently there is no deal. Should the prisoner swap negotiations fail, the full weight of responsibility will lie on Netanyahu's shoulders."
Prime Minister Benjamin Netanyahu also addressed the deal Sunday and noted during a meeting with Likud Knesset members that Israel will not release "terror symbols."
"We have no intention of freeing major terrorists and the release of terrorists to Judea and Samaria should be prevented," Netanyahu noted.