The U.S. consulate convoy had come to the Adei Ad outpost to look into complaints that Israeli settlers on Thursday had destroyed Palestinian-owned olive groves, Israel's Haaretz news website reported on Friday.
The convoy reportedly included Palestinian residents of the village of Turmus Ayya, according to Ynet, another Israeli news outlet.
"According to both Palestinian and settler sources, American security guards drew their weapons on the settlers," Ynet reported.
No injuries were reported from the incident.
An Israeli police spokeswoman said the delegation arrived at Adei Ad in U.S. diplomatic cars without first having coordinated the visit with Israeli authorities. She said the purpose of the trip was to inspect nearby trees that had been uprooted in what their Palestinian owners suspect was vandalism by Jewish settlers.
"Rocks were thrown at them by residents of Adei Ad. We are investigating. Arrests have yet to be made," the spokeswoman said. She said she did not know of any damage to the vehicles and had no further information on the delegates' identities.
An Adei Ad resident who spoke to Reuters on condition of anonymity said that he had not witnessed the incident but had been told by fellow settlers who were involved that the U.S. delegates came within 50 yards (metres) of the settlement in two diplomatic cars accompanied by local Palestinians.
The resident said several settlers went out to confront the group. He declined to confirm or deny that the settlers threw stones, but said two armed diplomatic guards briefly emerged from the cars.
"One had a pistol, the other an M-16, and they pointed them at the settlers," the resident said.
Asked about this account, the Israeli police spokeswoman said: "We have no indication that anyone in the U.S. delegation brandished weapons."
The Adei Ad resident said some 40 families live in the settlement. Around 500,000 Israelis live in such enclaves among 2.5 million Palestinians in the West Bank and East Jerusalem, which Israel captured in the 1967 war and which most world powers envisage as part of a future Palestinian state.
Tension has mounted in the occupied Palestinian territories since the kidnap and murder of three Israeli settlers last summer and the subsequent abduction and murder by Jewish settlers of a 16-year-old Palestinian boy.
Both incidents preceded a devastating Israeli military onslaught on the Gaza Strip in July and August that left over 2,160 Palestinians dead – the vast majority of them civilians – and some 11,000 injured.
Tensions in Jerusalem have escalated even further since late October, when Israel briefly closed occupied East Jerusalem's flashpoint Al-Aqsa Mosque compound after an extremist rabbi was shot and injured by a Palestinian man in West Jerusalem.