Rishi Sunak has said a crossing that will deliver vital aid to Gaza should open “imminently” after talks with Egyptian and Palestinian leaders.
The Prime Minister said that getting trucks with crucial supplies into the area was the “immediate priority” after he met with the Egyptian president Abdel Fattah El-Sisi.
Mr Sunak and the president of the Palestinian Authority, Mahmoud Abbas, also jointly condemned Hamas’s assault on Israel during their meeting in Cairo.
Their talks will be a seen as a coup for Mr Sunak, days after Mr Abbas cancelled plans to meet US President Joe Biden following a strike on the Al-Ahli Hospital in Gaza.
The meeting was due to take place in Amman, Jordan on Wednesday.
It came after the UN secretary general, António Guterres, flew to the crossing on the Egypt-Gaza border to plead for action.
A deal for aid to enter Gaza was brokered by US President Joe Biden on a one-day visit to Tel Aviv on Wednesday.
But it has been delayed amid negotiations and moves by the Egyptians to repair the crossing.
Mr Sunak said: “When this crisis unfolded, one thing we have prioritised consistently is getting the Rafah crossing opening.
“It’s been a feature of all my conversations, and I’m very pleased that that will now imminently happen.”
Mr Sunak was finishing a two visit to the Middle East in which he urged leaders to help prevent the conflict spreading across the region.
Earlier he stated he had agreed with the Amir of Qatar, who he met in Saudi Arabia, that world leaders must do “everything possible to prevent” the violence spilling over into other countries.
Tensions are rising as Israel’s troops prepare for a ground invasion of Gaza.
It has been under heavy bombardment from Tel Aviv, as Israel responds to an attack by Hamas on October 7 which killed 1,400 people.
The dangers of the Hamas conflict spilling over were illustrated after the United States said one of its warships had intercepted cruise missiles and drones launched from Yemen “potentially towards targets in Israel”.
Attacks against Israel have also been launched from Lebanon, where the Hezbollah group is backed by Iran, drawing retaliation from Tel Aviv.
Qatar is seen as a key player in the region, using its ties to Hamas to negotiate for the release of more than 200 hostages taken during the deadly assault on Israel and still missing.
During his meeting with Mr Abbas, Mr Sunak also reiterated the UK’s long-standing commitment to the two-state solution and “to achieving a future where Israelis and Palestinians can live in peace and security,” No 10 said.
In Israel on the first day of his tip, Mr Sunak told the country’s leadership the UK wanted it to “win” its fight against Hamas.
But he also emphasised that any action had to be in line with international law.
A spokesman said Mr Sunak thanked Qatar for their efforts to secure the release of hostages, including at least two British nationals who are known to be among those being held captive.
