The International Court of Justice affirmed Thursday that three islands in a disputed archipelago belong to Colombia, and said it would rule on a disagreement between Colombia and Nicaragua over other islands in the chain and the two countries’ maritime border.

Partially rejecting a Colombian challenge to its jurisdiction in a case brought by Nicaragua over ownership of the San Andres Archipelago, the U.N.’s highest judicial body said Colombian sovereignty over the islands of San Andres, Providencia and Santa Catalina was settled in a 1928 treaty.