An estimated 100 countries have signed bilateral extradition treaties with the United States, including all Latin American countries, Western European countries, Egypt, India, Australia, and New Zealand to name a few. Some 60 nations including China, Russia, several Middle Eastern and African countries have not. However, even if some countries signed extradition treaties they can still refuse to hand an individual over to the U.S. if that person is seeking asylum or if he/she would face the death penalty.
Source: The Economist: Daily Chart: Where can he go?