Whoever, having money of the United States in his possession or under his control, fails to deposit it with the Treasurer or some public depositary of the United States, when required so to do by the Secretary of the Treasury or the head of any other proper department or agency or by the Government Accountability Office, is guilty of embezzlement, and shall be fined under this title or in a sum equal to the amount of money embezzled, whichever is greater, or imprisoned not more than ten years, or both; but if the amount embezzled is $1,000 or less, he shall be fined under this title or imprisoned not more than one year, or both.