Israel and Hamas, the Palestinian militant group, have agreed to a ceasefire to end an 11-day conflict that has killed at least 230 Palestinians and 12 Israelis.

The truce, which came into force overnight, came a day after the US stepped up pressure on Israel to end its bombardment of the Hamas-controlled Gaza Strip, with US president Joe Biden telling Israel’s prime minister Benjamin Netanyahu on Wednesday that he “expected a significant de-escalation today on the path to a ceasefire”.

Netanyahu initially resisted, saying he was “determined to continue this operation until its aim is met”. But after Israel’s security cabinet met on Thursday, it said it had voted unanimously in favour of a “mutual and unconditional” Gaza ceasefire.

“I commended him for the decision to bring the current hostilities to a close within less than 11 days,” Biden said on Thursday after speaking to Netanyahu for the sixth time since the conflict started. “I believe we have a genuine opportunity to make progress. And I’m committed to working for it,” he said in remarks from the White House.

Biden said his administration had held “intensive high-level discussions, hour by hour, literally” in recent days with the aim of avoiding the sort of drawn-out conflict that has characterised past fighting between Israel and Hamas.

In a statement, Israel’s security cabinet held out the possibility that its military strikes could resume, saying: “The political leadership emphasises that it is the reality on the ground that will determine the future of the operation.”

Taher al-Nono, media adviser to Ismail Haniyeh, Hamas’ leader, said: “The Palestinian resistance will commit with this agreement as long as the occupation does.”

The ceasefire comes after Israeli warplanes and artillery pounded Gaza for more than a week, targeting Hamas militants but causing huge destruction across the densely populated, hemmed-in strip which is home to 2m people. At least 104 women and children have been killed in Gaza, according to Palestinian health officials.

Hamas, which fought three wars with Israel between 2009 and 2014, fired more than 3,700 rockets targeting cities and towns across Israel, and two Israeli children were killed.

The latest conflict began on May 10 after weeks of tensions in and around Jerusalem and it triggered the worst fighting between Israel and the Palestinians since the 2014 war with Hamas. It also sparked communal unrest between minority Arab Israelis and Jews, a rarity that unsettled political leaders and wider society in Israel, and widespread unrest in the occupied West Bank.

The ceasefire agreed late on Thursday was brokered by Egypt, which has mediated along with the US and Qatar. Cairo said it would send two security delegations to Tel Aviv and the Palestinian territories to follow up on implementation measures.

A regional official told the Financial Times that the mediation gathered momentum after Biden spoke to Netanyahu on Wednesday.

“There has been more momentum after Biden’s statement yesterday and I think the Israelis have hit most of their targets,” the official said. “The US has been helping with the pressure on Israel, they have been involved throughout, but yesterday was the first time they put on real pressure.”

António Guterres, the UN secretary-general, on Thursday described Gaza as “hell on earth” for children.

“The hostilities have caused serious damage to vital civilian infrastructure in Gaza, including roads and electricity lines, contributing to a humanitarian emergency,” he told the UN General Assembly. “Crossings into Gaza have been closed and power shortages are affecting water supplies.”

The regional official said Hamas wanted an end to the expulsion of Palestinian families from the Sheikh Jarrah neighbourhood of occupied East Jerusalem, a move that helped trigger the 11 days of violence; an end to curbs around al-Aqsa mosque, Islam’s third holiest site; and to ease the delivery of aid and reconstruction materials into Gaza. The mosque lies in a Jerusalem compound — known to Muslims as the Haram ash-Sharif, or Noble Sanctuary, and to Jews as Temple Mount — that is sacred to both religions.

The ceasefire negotiations had been held up in part by a Hamas demand that Israel stopped targeting senior leaders in the militant group with air strikes, an Arab diplomat said.

The Israeli army had tried to kill Hamas military leader Mohammed Deif twice in the current hostilities, the army told Israel’s Hebrew press on Wednesday, but he escaped on both occasions.

Israel’s military had also targeted associates of Deif, who is described in the local media as “Israel’s most wanted man”, in a May 12 air strike, the army said earlier. Negotiating a ceasefire before Israel’s military objectives were completed was also a complication, the Arab diplomat said.

Biden said the US would help Israel replenish its Iron Dome missile defence system, which he said had “saved lives of countless Israeli citizens, of Arab and Jew”. He said the US would also support reconstruction of Gaza in partnership with the Palestinian Authority, “not Hamas”, in a manner that would prevent the militant group from restocking its military arsenal.

“I believe the Palestinians and Israelis equally deserve to live safely and securely, and to enjoy equal measures of freedom, prosperity, and democracy,” he said.