the consulate may argue that eritrea was ethiopia before it became independent, in terms of international law (i.e. between 1962 when Selassie annexed it as a province and 1993 when independence was proclamed).
The Immigration and Nationality Act (INA) Section 202 [8 U.S.C. 1152] states in pertinent part under Rules for Chargeability, that each independent country, self-governing dominion, mandated territory, and territory under the international trusteeship system of the United Nations, other than the United States and its outlying possessions, shall be treated as a separate foreign state for the purposes of a numerical level established under subsection (a)(2) when approved by the Secretary of State. All other inhabited lands shall be attributed to a foreign state specified by the Secretary of State. For the purposes of this Act the foreign state to which an immigrant is chargeable shall be determined by birth within such foreign state. The INA §202(b) states that chargeability is determined by birth in a foreign state, so the determination is based on where the applicant is born, and not on where the applicant has a claim to nationality or citizenship. This distinction between chargeability and nationality matters precisely because of how the State Department determines visa availability. Aliens not qualifying as “immediate relatives” under family-based petitions, or for whom a visa is not immediately available, will receive a visa based on the availability for their country of chargeability, which may not necessarily be their country of nationality.
The only known exceptions to this rule are that 1) an Alien child may be charged to foreign state of either parent (where accompanying or following to join parent); 2) a spouse may be charged to state of accompanying spouse; 3) a USC who lost citizenship may be charged to a country of current citizenship or, if citizenship is non-existent, to country of last residence; or 4) an alien born in location where neither parent was born or had their residence may be charged to the foreign state of either parent. These exceptions, like the others, suggest that when it is in the alien’s best interest (or the interests of keeping a family together) to claim another country, the alien can be charged to a country other than its country of birth for immigration purposes. If no such consideration exists, then the country of birth controls.
If you fit one these exceptions (4 as 1-2-3 dont seem to apply) you can go to the interview with confidence.
If not, then, I dont know, someone else may come up with a better idea.