VIENNA — The new oil minister in Saudi Arabia, the de facto leader of the OPEC countries, had a message for the global market: Don’t expect us to influence the price of crude oil by adjusting supplies.

“I think managing in the traditional way that we tried in the past may never come again,” the minister, Khalid al-Falih, said on Thursday. “Certainly we will not go with certain price targets.”

The message — which came after the decision on Thursday by the 13-nation Organization of the Petroleum Exporting Countries to maintain high levels of oil production — is central to the changing strategy of the Saudi crude-oil complex. And it could foreshadow a period of volatility for oil prices because OPEC’s policies and the Saudis’ sway have long helped guide the markets.

In a sweeping directive in April, Saudi Arabia set forth plans to diversify its economy, reduce its dependence on oil and pull back on its government handouts. And what Mr. Falih does with Saudi Arabia’s oil — how much the kingdom decides to pump and where the money goes — is the biggest piece of the puzzle.