A Hamas statement on Sunday said the delegation had accepted an invitation extended by neighbouring Egypt.
The agenda will include talks over the controversial US embassy move, scheduled to take place on Monday.
The decision announced by US President Donald Trump in December has angered Palestinians, who view the eastern part of the city as the capital of their future state.
Thousands of Palestinians are expected to protest against the move from across the occupied Palestinian territories on Monday, including the Gaza Strip as part of the Great March of Return.
The Great March of Return includes rallies that are part of a weeks-long protest that will culminate on May 15 to mark what Palestinians refer to as the Nakba or “Catastrophe” – a reference to Israel’s establishment in 1948, when 750,000 Palestinians were forcibly removed from Palestine.
Since the protests began on March 30, Israeli forces have killed at least 49 Palestinians in the coastal enclave, and wounded more than 8,500.
For much of the last decade, Egypt has joined Israel in enforcing a crippling blockade that has deprived Gaza’s roughly two million inhabitants of most basic commodities, including food items, fuel and medicine.
Haniya is also expected to discuss the rekindling of the Hamas-Fatah reconciliation agreement that has largely been at a standstill for months, according to Hamas spokesperson Fawzi Barhoum.
Rival Palestinian faction Fatah, led by the Palestinian Authority in Ramallah that governs parts of the occupied West Bank, signed a reconciliation agreement with Hamas under Egypt’s auspices in October 2017, but the terms of the agreement signed in the Egyptian capital have not been implemented.
Ties between the two sides reached a new low in March when Fatah blamed Hamas for an explosion that targeted Palestinian Prime Minister Rami Hamdallah’s convoy during a visit to the Gaza Strip.
Haniya is expected to return to Gaza later on Sunday.