The Iranian constitution stipulates that the first vice president take over "in the event of the president's death, dismissal, resignation, absence or illness for more than two months".
Hamas said it appreciated Raisi's "support for the Palestinian resistance, and tireless efforts in solidarity" with Palestinians since the start of the Israel-Hamas war in Gaza following the group's October 7 attack.
As a young prosecutor in Tehran, Raisi sat on a panel that oversaw the execution of hundreds of political prisoners in the Iranian capital in 1988, as Iran's eight-year war with Iraq was coming to an end, rights groups say.
The decision was announced by a Pakistani Foreign Ministry spokesman on January 17, just a day after Iraq recalled its envoy from Tehran after civilians were killed in an IRGC missile strike in Irbil.
