A 20-year-old Palestinian man named Ayed Azzam Salim was shot and killed by Israeli forces in the West Bank on Friday.
Palestinian health officials confirmed the news, stating that the incident occurred near the town of Azzun.
The details of the incident remain unclear, and the Israeli Defence Forces has yet to comment.
The shooting has only added to the already heightened tensions in the region, which have been steadily rising since the latest wave of violence erupted between Israeli forces and Palestinian militants.
In a statement released on Saturday, the US Department of Defence conveyed Secretary Austin's call to Yoav Gallant, Israel's Minister of Defence, offering condolences for the deaths of two Israeli-British citizens in the West Bank and an Italian tourist in Tel Aviv in terror attacks that took place yesterday.
The statement also highlighted the Secretary's support for Israel following recent rocket attacks emanating from Lebanon and the Gaza Strip that injured Israeli civilians.
The Secretary emphasised his commitment to Israel's security against all threats, and urged steps to ensure a calm and peaceful holiday period for Jews, Muslims, and Christians. He welcomed efforts to de-escalate tensions and emphasised the importance of refraining from unilateral actions that exacerbate tensions.
According to the statement, Secretary Austin wished Minister Gallant a happy Passover and the two leaders agreed to remain in close co-ordination
The US Department of Defence statement reaffirmed the United States' strong partnership with Israel and its commitment to promoting stability and security in the region.
British-Israeli sister die in West Bank
A representative for the UK's Foreign, Commonwealth and Development Office confirmed that the two women killed in the incident held British citizenship.
“We are saddened to hear about the deaths of two British-Israeli citizens and the serious injuries sustained by a third individual,” the office said. “The UK calls for all parties across the region to de-escalate tensions.”
The women had moved with their family to a settlement in the occupied West Bank in 2005, Sky News reported, citing British officials in Jerusalem.
Medics said they pulled the three unconscious women from their car, which had apparently crashed after the attackers opened fire from a nearby vehicle, as tension flared after a night of cross-border fire.
The Magen David Adom ambulance service said the two women in their 20s were killed and the third, who is in her 40s, was seriously wounded and had been flown to hospital.
Hadassah Hospital in Jerusalem said the condition of the third victim was “very critical”.
The mayor of the Efrat settlement said the two dead women were sisters and the injured woman was their mother.
Oded Revivi said in a statement that the family is from Efrat. The father was driving ahead in another vehicle, he said.
The Israeli military said security forces were searching for the attackers. Army radio reported that a cordon had been set up around the nearby city of Jericho to help the search for the suspects.
Later in the day, Prime Minister Benjamin Netanyahu visited the site of the attack.
Militant group Hamas “congratulated” the “heroic” operation that was conducted in the occupied Jordan Valley and said that it was a “natural reaction” to Israel's recent actions in Jerusalem and Lebanon.
Israeli Defence Minister Yoav Gallant, meanwhile, said a Kalashnikov-type weapon was used.
Israeli President Isaac Herzog said the sisters were “pure souls … caught in a heinous and shocking murder”.
“Together with the people of Israel, I pray for the mother's healing and good news,” he added on Twitter.
Army radio also reported, citing investigators, that the perpetrators had fled using a second vehicle and left their car at the scene.
The incident took place near the junction of the Hamra settlement in the Jordan Valley.
The attack came after nightly raids by Israeli police on Al Aqsa Mosque in Jerusalem that inflamed regional tension and led to armed factions firing rockets at Israel from both Gaza and southern Lebanon.