Washington will impose sanctions on an Israeli group on Friday for attacking humanitarian aid convoys bound for starving civilians in Gaza, US officials told, in the latest move targeting actors Washington believes threaten the prospects for peace between Israelis and Palestinians.

The sanctions will target Tsav 9, a group with ties to Israeli army reservists and Jewish settlers in the Israeli-occupied West Bank, over activities including blocking, harassing and damaging aid shipments.

Palestinians have been desperately in need of aid as Israel continues its eight-month invasion and bombardment, which has killed at least 37,000 people, according to the territory's health ministry. Israel has also faced accusations of blocking aid, which it denies doing.

Right-wing elements in Israel's government, with links to the settler movement, have opposed US President Joe Biden's effort to forge a ceasefire agreement between Israel and Hamas to end the Gaza war that began with Hamas' attacks on southern Israel on Oct 7, which killed around 1,200 people, according to Israeli tallies.

The financial sanctions will be imposed under an executive order on West Bank violence Biden signed in February, which was previously used to impose financial restrictions on Jewish settlers involved in attacks on Palestinians as well as a Palestinian militant group.

"We're using the authority to sanction an ever-broadening selection of actors, targeting individuals and entities that threaten the peace, security and stability of the West Bank regardless of religion, ethnicity or location," Aaron Forsberg, director of the State Department's office of sanctions policy and implementation, said.

On May 13, members of Tsav 9 looted and then set fire to two aid trucks near the West Bank city of Hebron.

Hebrew for Order 9, a reference to call-up orders for Israeli military reservists - said after the May 13 incident it acted to stop supplies from reaching Hamas and accused the Israeli government of giving "gifts" to the Islamist group.

"For months, individuals from Tzav 9 have repeatedly sought to thwart the delivery of humanitarian aid to Gaza, including by blocking roads, sometimes violently, along their route from Jordan to Gaza, including transiting the West Bank," State Department spokesperson Matthew Miller said in a statement seen.

"They also have damaged aid trucks and dumped life-saving humanitarian aid onto the road."

The move freezes any assets the group holds under US jurisdiction and bars Americans from dealing with it.

Democracy for the Arab World Now, a US-based human rights group, this week called for Us sanctions on Tsav 9 and said the group raises funds from Israeli companies and Israeli and US non-profit organisations.

DAWN said in a statement that such vigilante groups have enjoyed impunity from Israeli authorities.

Palestinians and human rights groups have long accused the Israeli military and police of deliberately failing to intervene when settlers attack Palestinians in the West Bank.

Israel arrested four of those involved in the May 13 attack, including a minor, according to lawyers.

"We'll continue to use all tools at our disposal to promote accountability for those who attempt to undertake or perpetrate such heinous acts," Forsberg said. "We have raised this at all levels of the government of Israel and we expect that Israeli authorities will do the same."