The United States on Monday voiced concern over a Human Rights Watch report that Saudi border guards killed hundreds of Ethiopian migrants and urged a full investigation.
"We have raised our concerns about these allegations with the Saudi government," a State Department spokesperson said.
"We urge the Saudi authorities to undertake a thorough and transparent investigation and also to meet their obligations under international law."
The State Department said that the land border guards implicated in the report did not receive any US government funding or training.
The United States is a longstanding security partner of oil producer Saudi Arabia but has a fraught relationship over human rights, with President Joe Biden's administration criticizing the kingdom even while it pursues engagement.
Human Rights Watch in its report said that Saudi border guards "fired like rain" on Ethiopian migrants as they tried to cross from Yemen, killing hundreds last year.
A Saudi government source earlier called the allegations "unfounded."