The embassy in the Ukrainian capital Kiev has requested that the Foreign Ministry authorize the departure of "unnecessary staff and their families", CNN reports, citing several centrally located sources.
A State Department spokesman said they "have nothing to report right now", adding: "We are carrying out rigorous contingency planning, as we always do, in the event of a deteriorating security situation."
An embassy spokesman declined to confirm and referred CNN to the State Department in Washington.
Fox News also reports the news on Saturday and adds that an evacuation can begin as early as Monday, according to their sources.
Next week, the State Department is also expected to urge Americans to start leaving Ukraine on commercial flights, "while these are still available," Fox reports, citing a statement from a State Department official.
The financial news service Bloomberg was among the first to report the task on Friday.