VATICAN CITY — In the end, American-style transparency was no match for the Vatican’s obsession with secrecy.

Cardinals attending closed-door discussions ahead of the conclave to elect the next pope imposed a media blackout Wednesday, forcing the cancellation of the popular daily news briefings by U.S. cardinals that had provided crucial insights into the deliberations.

The official reason for the blackout was that some details of the secret discussions about the problems in the church appeared in the Italian newspaper La Stampa.

But speculation mounted that the underlying aim of the blackout was to silence the Americans, who have been vocal in their calls for disclosure about allegations of corruption and dysfunction in the Holy See’s governance before they enter the conclave to elect a successor to Benedict XVI.

As a result, the conflict appears to be a microcosm of the likely battle lines heading into the election: American and German cardinals have indicated they want a pope who will impose some order on the Vatican’s inner workings, while the Vatican-based cardinals are defending their record and seeking to end the discussion.

The Vatican denied it had exerted any pressure on the American cardinals to keep quiet and cancel their briefings. But the Vatican spokesman, the Rev. Federico Lombardi, made clear that the Holy See considered this week’s preconclave meetings to be secret and part of a solemn process to choose a pope, suggesting that he didn’t necessarily appreciate the Americans’ candor.

“The College (of Cardinals) as a whole has decided to maintain a line of an increasing degree of reserve,” he said.

The debate played out as the Vatican awaited the arrival of the last voting-age cardinal: Vietnamese Cardinal Jean-Baptiste Pham Minh Man, who was expected in Rome on Thursday. With his arrival, the College of Cardinals was expected to be able to set a date for the start of the conclave, where 115 men will select the next pontiff.