Jen Psaki, a spokeswoman for the State Department, said most of those killed in sectarian clashes in CAR were Muslims.
The Muslim rebel coalition, Seleka, took over the government in March and the conflict took on a religious tone when the anti-balaka Christian militia took up arms against rivals.
"This sectarian violence must end," Psaki said in a statement Wednesday.
The spokeswoman said the U.S. government was working in support of French and African Union peacekeepers, as well as international organizations, to bring peace to CAR.
Greek Foreign Minister Evangelos Venizelos, whose country holds the rotating presidency of the Council of the European Union, told European legislators in Strasbourg, France, the "social fabric" of CAR has been disrupted by tit-for-tat killings among Muslims and Christians.
Psaki added the U.S. government was calling on parties to the conflict in CAR to "work toward reconciliation rather than revenge."