Hamas political bureau chief Ismail Haniyeh has said that any agreements that exclude Hamas will be rejected, in a speech on Wednesday.
He emphasised that any post-war plans in Gaza must include the Palestinian Islamist group.
"Hamas exists to stay," he said. "The movement [Hamas] will decide, along with all national factions and the administration of the Gaza Strip after the war."
During his speech, Haniyeh blamed Israel for the deadlock in negotiations and preventing a truce or a hostage exchange deal from being completed, and said that by demanding Hamas amend its proposal, Israel has forced talks into a stalemate.
Haniyeh, who is currently based in Qatar, said the group was determined to pursue all means to end the war on Gaza, and is open to mediation efforts.
However, he reiterated that any deals agreed upon must meet the group’s key demands.
"Any efforts or agreement must secure a permanent ceasefire, a comprehensive pull-out from all of the Gaza Strip, a real prisoner swap deal, the return of the displaced, reconstruction and the lifting of the blockade," he said.
The comments come as an Israeli delegation travelled to Egypt on Wednesday to discuss Israel’s invasion of Rafah.
"The main issue raised in the talks was the deep crisis between Israel and Egypt since the beginning of the war," Israel's Kan news broadcaster reported.
"This has worsened since Israeli army forces entered the outskirts of Rafah, and the threats heard from Egyptian officials to reduce the level of [diplomatic] relations," the report added.
Israeli media also reported that the visit aimed "to calm Egyptian anger" over the Rafah invasion.
Egypt’s foreign minister Sameh Shoukry called on Israel to stop its military operations in Rafah, stressing that the attacks were obstructing the delivery of aid.
Earlier this month, Hamas said the "ball is now completely" in Israel’s court after the group accepted a ceasefire proposal put forward by mediators.
The deal, the group said, involved a withdrawal of Israeli forces from Gaza, the return of Palestinians displaced by the war, and the exchange of hostages held by Hamas for Palestinian prisoners detained in Israel, with the aim of a "permanent ceasefire".
Israel’s war on Gaza has killed over 35,200 since 7 October and wounded over 79,000 others. The bombardment has devastated entire neighbourhoods and destroyed the enclave’s infrastructure.
Around 1.4 million forcibly displaced Palestinians are currently sheltering in Rafah, which Israel has started attacking.
