It operates under FAR Part 91.109(b)(1)
It applies to FAA hours only and you must have an FAA IR.
It
will not count towards EASA.
Some NAA's provide guidance on this :
Logging of Flight Hours gained in the USA
Some flight hour recording practices allowable in the USA do not comply with European
and UK requirements. In particular:
• 2 pilots flying together in a single pilot aircraft both claiming P1 hours;
• One pilot accompanying another on news gathering or traffic control flights and
claiming P1/PIC when they have not acted as Captain or signed for the aircraft.
Flying hours of this nature cannot be credited towards the requirements for Part-FCL