Justices were skeptical Monday that the case was an exception to other lawsuits against defense contractors, which usually get immunity in such litigation.
U.N. High Commissioner for Human Rights Volker Türk called for an investigation into the strikes in what appears to mark the first such UN condemnation.
The U.S. military is sending an aircraft carrier to the waters off South America, in the latest escalation and buildup of military forces in the region.