Iran's influence over Hamas has increased in recent months and Teheran is playing a key role in the terror group's decision-making process regarding whether to extend the cease-fire with Israel that will expire on Friday, defense officials said Monday. According to the officials, Egypt - which for years was the main address for dealings with Hamas - has lost its authority over the terror group and is being replaced in part by Iran. The Gaza issue has been a source of contention between Teheran and Cairo in recent weeks. As an example of Egypt's decline, the official noted that in November, Hamas rejected an Egyptian request to come to Cairo for talks with Palestinian President Mahmoud Abbas. "Egyptian influence over Hamas has dropped," a senior defense official said Monday. "Iran's influence, on the other hand, is on the rise." On Monday, some 80 trucks carrying fuel and basic humanitarian supplies were allowed into the Gaza Strip via the Kerem Shalom and Nahal Oz Crossings. Defense officials said that the crossings were specially opened to allow the transfer of the supplies, which Israel is obligated to allow into Gaza even when the crossings are officially closed. Defense Minister Ehud Barak said Monday that he would not be deterred from launching a military operation in Gaza. "I am not deterred from an operation in Gaza but am also not running into Gaza," Barak said, during a meeting with visiting Austrian President Heinz Fischer. "If there will be quiet it will be met by quiet. If the truce will be breached and there is no choice, we will operate in the right way and at the right time." Although the truce began on June 19, "it was agreed explicitly that there is no expiration date" in the agreement, head of the Defense Ministry's Diplomatic-Security Bureau Maj.-Gen. (res.) Amos Gilad said Monday, a day after returning from talks with Egyptian officials in Cairo. "In the end, the test is the calm and the benefit the residents have had for long months, even though it is relative calm," he added. Exiled Hamas leader Khaled Mashaal however, said on Sunday that the truce would not be renewed when it expires on Friday. Other Hamas officials said that the group had not yet made a decision on whether or not they would seek to renew the agreement. Asked whether any progress had been made on the issue of captured soldier Gilad Schalit during the talks in Egypt that he had on Sunday, Gilad said the only real test was "whether he's [in Israel] or not." He said that the issue of the cease-fire with Hamas was crucial to freeing the captured soldier, and expressed hope that Schalit "would return alive and well." Meanwhile, Israel released 224 Palestinian prisoners Monday in a gesture to Palestinian Authority President Mahmoud Abbas. Jubilant detainees waving Palestinian flags jumped on the roof of one of the buses carrying them to freedom. The buses headed from an IDF checkpoint to Abbas's headquarters in nearby Ramallah, where he hugged and kissed each former detainee. Initially, Israel was to free 227 prisoners. However, Israeli Prison Service spokesman Yaron Zamir said only 224 were freed, and the release of three others was still under review. Eighteen of the prisoners were released to Gaza. Abbas told the detainees in Ramallah that he would work to win the release of all the remaining prisoners in Israeli jails. "Our happiness will not be complete until all of the 11,000 prisoners are freed," Abbas said. One of the prisoners, Abdel Nasser Hussein, 28, had been arrested at dawn on his wedding day 30 months ago. His fiancee, Alaa Issa, showed up smartly dressed in a matching coat and head scarf Monday, bearing a bouquet of red roses. They hugged and kissed. "It's indescribable happiness," said Hussein, a former member of the Palestinian security forces. "You can't put a price on freedom, and my hope that is that the president will keep working for my colleagues to be released." After exchanging rings, they walked arm-in-arm, their friends and family clapping and singing a traditional wedding song. They plan to marry in two weeks. AP contributed to this report.