Israeli Defence Minister Yoav Gallant approved the administrative detention of four Israeli extremists accused of violence against Palestinians in the occupied West Bank last week.
The signing of the controversial measure on Wednesday, which is rarely used against Jews, can technically last indefinitely and prevent suspects from seeing the evidence against them.
Almost 1,000 Palestinians are currently held under the same circumstances.
Mr Gallant's rare move came shortly after US Secretary of State Antony Blinken “conveyed concern” over the escalation of violence in the occupied West Bank during a phone call with Israeli Foreign Minister Eli Cohen, the State Department has said.
Mr Blinken also discussed Israel's regional ties and efforts to counter Iranian influence during talks on Tuesday.
Recent violence in the West Bank has directly affected US citizens, Washington said.
Days of deadly settler violence in Palestinian villages following the death of four Israelis in an attack near a West Bank settlement has reignited fears of a broader conflict.
A Palestinian was shot dead in the village of Turmus Aya last week as dozens of homes and vehicles were set on fire by Israeli settlers across the West Bank.
The village has a particularly high number of Palestinian-American residents, many of whom visit their homes in the summer.
The spate of attacks led Israeli Defence Minister Yoav Gallant to condemn the violence in a rare call with Palestinian leaders.
There are also concerns that Israel's current government, led by Prime Minister Benjamin Netanyahu and widely considered the most right-wing in the country's history, is not willing to deal with violence from settlers.
Many cabinet ministers openly advocate for more land grabs in the West Bank.
Far-right National Security Minister Itamar Ben-Gvir called settler vigilantes “sweet kids” and said the issue is being overblown during a government meeting on Tuesday, Israeli public broadcaster Kan reported.
Mr Ben-Gvir's comments came days after Orit Strook, a minister from the Religious Zionist party, condemned the country's security services chiefs, comparing them to mutinous Wagner Group mercenaries who sought to overthrow the Russian government at the weekend.
Her comments were a response to rare criticism from Israeli security chiefs, who had said recent settler attacks constituted nationalist terror and “contradict all Jewish values”.
Mr Blinken's call comes days after the US announced it is to end scientific co-operation with Israeli institutions in the West Bank, a sign of the growing cracks between Washington and its ally.
The decision was announced on Monday, the same day the Israeli government's Supreme Planning Council approved the construction of about 5,700 more settler homes in the occupied West Bank.
The State Department said it was “deeply troubled” by the decision to expand settlements.
Although the US has denounced Israeli settlements, deemed illegal under international law, it is often criticised for not taking stronger action to oppose their construction.
Mr Netanyahu's cabinet recently eased restrictions on settlement construction, a key priority of the government, which is considered the most right-wing in the country's history.
Washington said on Monday that it would monitor Palestinian-American access to Israel and the West Bank as it considers adding Israel to its visa waiver programme.
The pilot initiative, to be launched next month, will involve US delegates keeping tabs on Palestinian-American travel through Ben Gurion Airport and across West Bank checkpoints.
