ALGIERS, Algeria—OPEC producers largely agree that oil prices above $80 a barrel would be too high. But there is widespread disagreement on how the cartel and its allies should contain crude prices once U.S. sanctions banning Iranian oil sales take effect in November.

Members of the Organization of the Petroleum Exporting Countries and a Russia-led alliance are meeting in the Algerian capital on Sunday to debate options for stabilizing prices, which have soared 40% in the past year. At the same time, some OPEC member nations...