Israeli Prime Minister Benjamin Netanyahu on Sunday said he would push ahead with a military offensive in Rafah, where 1.5 million displaced Palestinians are sheltering, despite US President Joe Biden's warning that doing so would be a "red line." The Israeli leader's remarks come as the Islamic holy month of Ramadan begins and ceasefire talks stall. Israeli officials had previously warned that if hostages held in Gaza weren't home by the start of Ramadan, they would launch a military offensive into Rafah. Netanyahu said the operation in the southern city would not last more than two months, but did not provide specifics on the timeline. He also denied Biden's claim that he is "hurting more than helping" Israel in failing to limit civilian casualties in Gaza. The Biden administration is not anticipating that Israeli forces will imminently expand their military operations into Rafah, two US officials told CNN. The United Nations aid chief has warned that a ground invasion into Rafah could lead to "a slaughter." Meanwhile, German Chancellor Olaf Scholz has called for a longer-lasting ceasefire in the Gaza war "ideally during Ramadan." "Such a ceasefire should ensure that the Israeli hostages are finally released and that more humanitarian aid finally arrives in Gaza," the chancellor said in a video message on Sunday. Scholz said he is "certain that the vast majority of Israelis and Palestinians want peace." Hamas remains open to mediated talks with Israel, the militant group's political leader said, after the two sides failed to reach a truce agreement and hostage release deal before Ramadan. But Ismail Haniyeh insisted that a permanent ceasefire in Gaza and the withdrawal of all Israeli forces was the only way forward to an agreement. A member of Hamas' political bureau told CNN there were "no dates yet" for Hamas negotiators to return to Cairo to resume talks. — CNN