Britain's minister for development expressed concern on Thursday for refugees across the Middle East as regional tensions soar, warning that "the most vulnerable" would suffer first in an escalation.

Fears of military escalation that would pit Iran and its allied armed groups against Israel have grown since two high-profile killings blamed on Israel last week, as the Israel-Hamas war rages on in the Gaza Strip.

Minister Anneliese Dodds told AFP in an interview during a visit to Jordan that "currently, sadly, we are in a concerning situation geopolitically".

"We must see a de-escalation. It's in no one's interest to have an escalation of conflict," she added.

"Those who would suffer first would be those who are the most vulnerable in this region," Dodds said.

About 625,000 Syrian refugees in Jordan are registered with the United Nations, though Amman estimates at 1.3 million the number of Syrians who have fled to the neighboring kingdom since war broke out in 2011.

Jordan also hosts 2.2 million registered Palestinian refugees.

In Jordan, "there are many Syrian refugees as well as Palestinian refugees ... So it's been a very important visit for me to understand more about the situation and to convey that message around the need for de-escalation," Dodds said.

'Concerning humanitarian situation' 

Iran has threatened a "harsh punishment" for the killing Wednesday of Ismail Haniyeh, the political leader of Palestinian militant group Hamas, in an attack in Tehran blamed on Israel, which has not claimed responsibility for it.

Lebanon's Iran-backed Hezbollah movement has separately vowed retaliation for the Israeli killing of its military chief Fuad Shukur in Beirut, just hours before Haniyeh's killing.

Israel said the strike that killed Shukur was a response to rocket fire that killed 12 children and teenagers in the annexed Golan Heights.

During her visit, Dodds said she had "seen the work that has been going on from Jordan ... to try and tackle the concerning humanitarian situation in Gaza."

The vast majority of Gaza's 2.4 million people have been displaced at least once during the war, which has sparked a dire humanitarian crisis and warnings of famine since it began on Oct. 7.

With "a humanitarian crisis in Gaza and large numbers of people displaced more broadly in the region, we need to make sure that there is that de-escalation," she said.

Dodds referred to her Labour government's announcement of six million pounds ($7.6 million) in aid to support "particularly water and sanitation for 55,000 people in Gaza," which she said "is going to be directly focused on the needs of the most vulnerable" in the besieged territory.

Hamas's Oct. 7 attack on southern Israel that started the Gaza war resulted in the deaths of 1,198 people, mostly civilians, according to an AFP tally based on official Israeli figures.

Militants also seized 251 people, 111 of whom are still held captive in Gaza, including 39 the Israeli military says are dead.

Israel's retaliatory military campaign in Gaza has killed at least 39,699 people, also mostly civilians, according to the health ministry in the territory.