The embassy released a statement Thursday calling on the perpetrators to be held accountable.
"The U.S. Embassy condemns in the strongest terms the recent targeted attacks on humanitarian workers and their compounds in South Sudan, including those that have led to the deaths of three South Sudanese humanitarian workers and injury to others," the statement said.
"We renew our call for South Sudan’s leaders to act with urgency to end subnational violence and to hold accountable those responsible for attacks targeting civilians and humanitarian organizations, as well as for abductions and other human rights violations."
The embassy added that it supports "those who work for peace and stability in South Sudan.
Peter Van der Auweraert, the U.N.’s acting humanitarian coordinator in South Sudan, on Monday also condemned the attack on humanitarian workers and U.S. assets in Pibor of the Greater Pibor Administrative Area.
Several armed attackers broke into an international NGO compound in Pibor and beat one humanitarian worker who ended up requiring medical attention. The U.N. humanitarian agency said the attackers targeted the NGO for cash and other assets.
South Sudan's Minister of Information Michael Makuei declined to comment on the remarks from the U.S. Embassy, saying he was attending a Reconstituted Joint Monitoring and Evaluation Commission meeting.
Van der Auweraert said attacks on humanitarians who provide critical services to the most vulnerable people are "beyond comprehension."
"The ongoing violent attacks against humanitarians inadvertently hamper the delivery of much needed life-saving support to millions of people affected in times of escalating conflict," he added.
He said it is the duty of South Sudan authorities to protect humanitarian workers and civilians and called on authorities find those responsible for the attacks.
According to the U.N., South Sudan is one the most dangerous places for aid workers with nine humanitarian workers killed and 450 incidents of harassments in 2022. Three humanitarian workers were killed in the country this year.