Venezuela’s government and the opposition ended a round of negotiations on Wednesday night with no agreement, a setback for those bidding to unseat President Nicolás Maduro, who have seen their options narrow.

Few had expected the talks, held in Norway this month, to break through the political turmoil that has gripped Venezuela since January.

But the negotiations marked a change in strategy by the opposition leader, Juan Guaidó. He had resisted such talks in the past, instead calling for Mr. Maduro’s immediate resignation — even urging the military to depose him.

While the opposition said it was open to more talks in the future, it signaled that it would now turn back to its original approach, issuing a statement that called again for Mr. Maduro’s ouster, along with “a transitional government and free elections as the means to solve the tragedy from which Venezuela is suffering.”