Taiwan and North Korea are the only two countries I've found that seem to have no extradition and no (formal) interface to law enforcement abroad through Interpol.
Palau, Tuvalu and Micronesia in the Pacific are not members of Interpol, but they do have extradition treaties with the US, and then there are a host of countries in Interpol that have no US extradition.
Palau, Tuvalu and Micronesia in the Pacific are not members of Interpol, but they do have extradition treaties with the US, and then there are a host of countries in Interpol that have no US extradition.