(Corrects the number of Blinken trips to the Middle East to nine from 10 in second paragraph)
By Humeyra Pamuk
WASHINGTON (Reuters) -U.S. Secretary of State Antony Blinken is set to arrive in Israel on Sunday as part of Washington's intensifying diplomatic push to achieve a ceasefire in Gaza that will end the 10-month-old war between Israel and Hamas.
The top U.S. diplomat's ninth trip to the region since the war began in October last year comes days after the United States put forward bridging proposals that it and mediators Qatar and Egypt believe would close gaps between the warring parties.
U.S. officials cite fresh optimism to bring the deal over the finish line but also caution that there is still work to be done.
"What we've done is taken the gaps that remain and have bridged those in a way that we think basically is a deal that is now ready to close and implement and move forward," a senior Biden administration official told reporters on Friday.
In Israel, Blinken is expected to meet with the Israeli prime minister and other senior officials.
The negotiations are taking place in the shadow of a feared regional escalation. Iran has threatened to retaliate against Israel after the assassination of Hamas leader Ismail Haniyeh in Tehran on July 31.
Washington has repeatedly warned Iran not to go ahead with any retaliatory action against Israel. The U.S. official said such an act could have "cataclysmic" consequences, particularly for Iran.
Foreign ministers of the United Kingdom, France, Germany and Italy in a joint statement threw their support behind the ongoing ceasefire talks, urging all sides to avoid any "escalatory action."
Talks on how to implement the deal are expected to continue early next week, before senior officials reconvene in Cairo, with the aim to conclude the deal later in the week in Cairo.
Israel's negotiating team on Saturday expressed "cautious optimism" on the possibility of advancing a deal, according to a statement on Saturday from Prime Minister Benjamin Netanyahu's office.
Hamas spokesman Jihad Taha told Al Jazeera TV on Saturday that Israel had added conditions in the ceasefire talks and accused Netanyahu of using them to hinder efforts.
Even as hopes grew for a ceasefire, war raged on. At least 17 Palestinians were killed and dozens wounded in an Israeli strike in the Gaza town of Zawayda on Saturday, health officials said, as Israel issued new evacuation orders, citing Hamas rocket fire nearby.
The latest round of war in the decades-old Israeli-Palestinian conflict began on Oct. 7 when Hamas fighters rampaged into Israel, killing around 1,200 people and seizing around 250 hostages according to Israeli tallies.
Israel's subsequent military campaign has reduced much of Gaza to rubble and killed more than 40,000 Palestinians, mostly civilians, according to Palestinian health authorities. Israel says it has eliminated 17,000 Hamas fighters.