What two reasons does Romeo give Balthasar to go to the Capulets' tomb?

Romeo tells Balthasar that he wants to see Juliet’s face again and get the ring.

Juliet faked her death with the special potion from Friar Laurence, and he was supposed to get a letter to Romeo. The letter was delayed by a plague. As a result, Romeo thinks Juliet is really dead.

Romeo tells Balthasar he just wants to see Juliet’s face again and get the ring, but in fact he has a vial of poison to kill himself.

Why I descend into this bed of death,
Is partly to behold my lady's face;
But chiefly to take thence from her dead finger
A precious ring, a ring that I must use
In dear employment (Act V, Scene 3).

Balthasar doesn't believe Romeo. He hides at the tomb. Romeo goes inside and sees Paris there. 

Romeo is not happy to see Paris. They fight, and Romeo kills Paris. Then he goes to Juliet, and he takes the poison. Juliet wakes up to find him dead. There is no poison left, so she takes Romeo's dagger and kills herself.