Hmm.. Well when operating outside US airspace, I believe it is required to comply with the aviation rules of that country. If the country is a "Member State" under ICAO, then ICAO ANNEXES would most likely apply. UNLESS: that "state" filed a "difference" with ICAO.
International flying can get very complicated. I don't know the answer, but if you need help, I can get some contacts for you in the IFO world.

ICAO Annexes include "Standards and Recommended Practices" (SARP's). The "standards" are enforceable like 14 CFR.