Israeli leaders have harshly criticised an expected decision by the US to impose sanctions on a unit of ultra-Orthodox soldiers in the Israeli military.

The decision, expected as soon as Monday, would mark the first time the US has ever imposed sanctions on a unit inside the Israeli military and further strains relations between the two allies, which have grown increasingly tense during Israel’s war in Gaza.

While US officials declined to identify the sanctioned unit, Israeli leaders and local media identified it as Netzah Yehuda — an infantry battalion founded roughly a quarter of a century ago to incorporate ultra-Orthodox men into the military.

Many religious men receive exemptions from what is supposed to be compulsory service.

Israeli leaders condemned the decision as unfair, especially at a time when Israel is at war, and vowed to oppose it.

Prime Minister Benjamin Netanyahu said: “If anyone thinks they can impose sanctions on a unit in the IDF, I will fight it with all my might.”

Netzah Yehuda, or Judea Forever, has historically been based in the occupied West Bank and some of its members have been linked to abuses against Palestinians.

It makes up just a small part of Israel’s military presence in the territory.

In a statement on Sunday, the army said its Netzah Yehuda soldiers “are currently participating in the war effort in the Gaza Strip”.

“The battalion is professionally and bravely conducting operations in accordance to the IDF Code of Ethics and with full commitment to international law,” it said.

It said that if the unit is sanctioned, “its consequences will be reviewed”.

Secretary of State Antony Blinken said on Friday that he had made a decision on reviews of allegations that several Israeli military units had violated conditions for receiving US assistance outlined in the so-called Leahy Law and that they would soon be made public.

Benny Gantz, a member of Israel’s War Cabinet, said in a statement that he spoke Sunday evening with Mr Blinken and told him the decision is a “mistake” because it would harm Israel’s international legitimacy during wartime and because Israel’s judicial system is “strong and independent”.

The officials said about five Israeli units were investigated and all but one had been found to have taken action to remedy the violations.

The Leahy Law, named for former Senator Patrick Leahy, bars US aid from going to foreign military units that have committed human rights abuses.