Hamas has set a one-week ultimatum to the Israel Defense Forces to pull out from Gaza.
According to the report, Ahmadinejad telephoned Mashaal and told him, "This is only the beginning of victory." He added that "pressure must be exerted for a complete withdrawal" of the IDF soldiers from the Strip and for the opening of the Gaza crossings.
The Iranian president went on to say that "the Zionist criminals must be prosecuted".
Some 200 trucks carrying humanitarian aid were allowed into Gaza on Monday. Some 130 of entered the Strip through the Kerem Shalom crossing and 60 through the Karni crossing. About 400,000 liters of diesel oil were sent into Gaza through the Nahal Oz terminal.
In total, some 40,000 tons of humanitarian equipment have been sent into Gaza since the start of the military operation.
Hamas leader Ismail Haniyeh said on Sunday that Israel's three-week offensive in Gaza was a failure and had not cowed the Palestinians.
"The enemy has failed to achieve its goals," Haniyeh said in a speech broadcast on Hamas television. Though he called the war, in which more than 1,300 Gazans and 13 Israelis died, a "popular victory" for Palestinians, he said Hamas' decision to declare a truce on Sunday was "wise and responsible".
On Sunday afternoon, senior Hamas official Ayman Taha announced an immediate ceasefire by the organization's fighters and allied groups in the Gaza Strip, adding that the Islamists gave Israel a week to pull out its troops.
"Hamas and the factions announce a ceasefire in Gaza starting immediately and give Israel a week to withdraw," Taha said. The Islamic Jihad joined the ceasefire announcement.
The declaration was made shortly after another Hamas source told Ynet that the pause is aimed at allowing the organization's delegation in Cairo to receive clarifications on the completion of the withdrawal, the opening of the crossing and the removal of the blockade imposed on Gaza.