Article 12(3) of the Rome Statute states that a non-member can consent to the jurisdiction of the ICC.  

The enforcement of a warrant issue is rooted in the principle of universal jurisdiction.  Universal Jurisdiction, however, is highly problematic as it requires that the member state prosecute or extradite.  In the case of prosecution, depending on the state and the limitations that they impose on jurisdiction, they may not be able to prosecute.  As it relates to extradition, some states have existing laws that prevent extradition to a state where it cannot be assured that the due process will be carried out.