如果您迟到了，有可能要重新预约面谈时间。我们会接受最多晚于面谈时间30分钟内到达的签证申请人。如晚于此时间，您可能会被要求重新预约面谈时间。

If you are late for your visa interview, you may need to schedule a new one. We will honor appointments for up to 30 minutes past the originally scheduled time. If you arrive later than this time, you may be asked to schedule a new appointment.

来源：2017-04-26美国驻华大使馆美国驻华大使馆