Puzzler of the Day

This is one of many "knights and knaves" puzzles, which were created by mathematician Raymond Smullyan.  The setting for most such puzzles is on an island which is inhabited by two types of people, knights and knaves. Knights always tell the truth and knaves always lie.

A visitor to the island encounters two inhabitants, A and B.

A says: B is a knave.

B says: A and I are both knights.

Question: What are A and B? Knight or knave?