Rule 18. Sentence

(a) Entry of a Judgment of Guilty. Upon plea or entry of a judgment of guilty, sentence shall be imposed without unreasonable delay. Before imposing sentence, the court shall afford counsel an opportunity to speak on behalf of the defendant and shall address the defendant personally and ask the defendant if the defendant wishes to make a statement in the defendant's own behalf and to present any information in mitigation of punishment.

(b) Withdrawal of Plea. A motion to withdraw a plea of guilty may be made only before sentence is imposed.