Israel, the White House and Egypt have said limited aid will be allowed to travel into Gaza through the Rafah border crossing with Egypt in the coming days. Foreign passport-holders are also expected to be allowed out under any deal to reopen the crossing, after many headed to the vicinity in recent days seeking to leave. Meanwhile, Israel has called on people in Gaza to move southwards closer to Rafah to shelter from bombardment. Here is a look at the situation and the history of the crossing. What is the Rafah border crossing? The Rafah crossing is Gaza’s only connection to Egypt. It is the sole route for aid to enter Gaza directly from outside Israel and the only exit that does not lead to Israeli territory. It has become a focus in the intensifying conflict between Israel and the Palestinian militant group Hamas as hundreds of thousands of Palestinians have headed towards southern Gaza after Israel warned them to leave Gaza City and the north. Since Hamas took control of Gaza in 2007, Egypt has helped enforce a blockade of the enclave and heavily restricted the flow of people and goods through the crossing. Like the main crossings with Israel, restrictions have sometimes been eased but not lifted, and travellers need security clearance and lengthy checks to pass. In 2008, tens of thousands of Palestinians crossed into Sinai after Hamas blasted holes in border fortifications, prompting Egypt to build a stone and cement wall. Egypt has acted as a mediator between Israel and Palestinian factions during past conflicts and periods of unrest. But in those situations it has also locked down the border, allowing aid to enter and medical evacuees to leave but preventing any large-scale movement of people. How long until aid reaches Gaza? Biden said Egypt’s president agreed to open the crossing and to let in an initial group of 20 trucks with humanitarian aid. If Hamas confiscated aid, “it will end”, he said. The aid would start moving Friday at the earliest, White House officials said. He added that the 20 trucks represented a “first tranche” but “150 or something” trucks were waiting in total. Whether the rest were allowed to cross would depend on “how it goes”. Egypt says the roads across the border need to be repaired after they were hit by Israeli airstrikes. More than 200 trucks and 3,000 tonnes of aid are positioned at or near the Rafah crossing, according to the head of the Red Crescent for North Sinai, Khalid Zayed. Supplies would go in under supervision of the UN, the Egyptian foreign minister, Sameh Shoukry, told Al Arabiya TV. Asked if foreigners and dual nationals seeking to leave would be let through, he said: “As long as the crossing is operating normally and the [crossing] facility has been repaired.” Previous assurances from the US that the border would open have not materialised. Why has Egypt been reluctant to open the border to civilians? Egypt and Jordan flank Israel and share borders with Gaza and the occupied West Bank, respectively. Both have been reticent to allow entry to displaced Palestinians. The Egyptian president, Abdel Fatah al-Sisi, made his toughest remarks yet on Wednesday, saying the war was not just aimed at fighting Hamas, which rules the Gaza Strip, “but also an attempt to push the civilian inhabitants to … migrate to Egypt”. He warned this could wreck peace in the region. Palestinians could instead be moved to Negev desert in Israel “till the militants are dealt with”, Sisi told a joint press conference in Cairo with the German chancellor, Olaf Scholz. “What is happening now in Gaza is an attempt to force civilian residents to take refuge and migrate to Egypt, which should not be accepted,” Sisi added. Referring to the Egyptian position at a Beirut press conference, the Hamas official Osama Hamdan called for “rallying around this position and supporting it on the popular and Arab official level because this represents real protection for our Palestinian people”. What is the security situation in southern Gaza? Israeli strikes on Gaza have continued in recent days, including on cities in the south that Israel had described as “safe zones” for civilians. Local officials in Khan Younis, less than 6 miles (10km) from the Rafah crossing, told the BBC three Israeli airstrikes there had killed 100 people. Most of them had been displaced, the officials said. Seven children were among the dead. Local medics also confirmed the children were killed in a strike. There was no immediate comment from the Israeli military. A series of explosions, believed to be airstrikes, hit a home in Deir al-Balah, also in southern Gaza, the Associated Press reported. The body of Hiam Musa, the sister-in-law of an Associated Press photojournalist, Adel Hana, was recovered from the wreckage on Wednesday evening, the family said. They did not know who else was under the rubble. “It doesn’t make sense,” Hana said. “We went to Deir al-Balah because it’s quiet; we thought we would be safe.” The Israeli military said it was investigating. More than 1 million Palestinians have fled their homes – roughly half of Gaza’s population. Those escaping the north and Gaza City to move south have crowded into UN schools or the homes of relatives. With Israeli airstrikes relentlessly pounding the Gaza Strip, displaced Palestinians increasingly feel that no place is safe.