During the blockade of Tripoli by the squadron of the United States, a small cruiser, under the flag of Tunis, with two prizes (all of trifling value,) attempted to enter Tripoli, was turned back, warned, and attempting again to enter, was taken and detained as a prize by the squadron. Her restitution was claimed by the bey of Tunis, with a threat of war so serious, that, on withdrawing from the blockade of Tripoli, the commanding officer of the squadron thought it his duty to repair to Tunis with his squadron, and to require a categorical declaration whether peace or war was intended. The bey preferred explaining himself by an ambassador to the United States, who, on his arrival, renewed the request that the vessel and her prizes should be restored. It was deemed proper to give this proof of friendship to the bey, and the ambassador was informed the vessels would be restored. Afterward he made a requisition of naval stores to be sent to the bey, in order to secure peace for the term of three years, with a threat of war if refused. It has been refused, and the ambassador is about to depart without receding from his threat or demand. Under these circumstances, and considering that the several provisions of the act, March 25th, 1804, will cease in consequence of the ratification of the treaty of peace with Tripoli, now advised to and consented to by the Senate, I have thought it my duty to communicate these facts, in order that Congress may consider the expediency of continuing the same provisions for a limited time or making others equivalent. SIXTH ANNUAL MESSAGE.--DECEMBER 2, 1806. _To the Senate and House of Representatives of the United States in Congress assembled_:--