Between five and 10 service members will go to western Ukraine next week for what will be a second round of coaching and mentoring members of the Ukraine military, who will then go on to become trainers.
The official discussed the deployment on condition of anonymity because the official was not authorised to speak on the record.
Last year, the US trained about 300 Ukrainian troops on battlefield medicine. US officials are continuing to review the range of instruction and other aid that can be provided to Ukraine.
