The US government has imposed sanctions on what it terms a violent extremist Israeli group for repeatedly thwarting deliveries of humanitarian aid to the Gaza Strip.

The US State Department issued a statement on Friday, announcing the sanctions, which include asset freezes.

The statement accused members of the group Tzav 9 of repeatedly seeking to thwart aid deliveries for months by such means as "blockading roads, sometimes violently" along the route from Jordan to Gaza.

The group's members are also alleged to have looted and set fire to two trucks in the West Bank carrying humanitarian aid destined for civilians in Gaza in May.

The group is largely comprised of Jewish settlers in the West Bank.

The State Department said: "We will not tolerate acts of sabotage and violence targeting this essential humanitarian assistance. We will continue to use all tools at our disposal to promote accountability for those who attempt or undertake such heinous acts."

The department also called on Israel to address the issue. It said, "The Government of Israel has a responsibility to ensure the safety and security of humanitarian convoys."

The United Nations says more than 1 million Palestinians in Gaza do not have enough clean drinking water and face desperate levels of hunger. It also points out that over 50,000 children require treatment of acute malnutrition.