Stephen I. Miran, who was appointed to the Fed last year by President Trump, issued his sixth straight dissent and voted for a quarter-point cut. Presidents from three of the regional reserve banks supported Wednesday’s decision to hold rates steady. But they wanted the Fed to signal more explicitly in its policy statement that the next move from the central bank was not necessarily another rate cut.

Instead, the Fed maintained in its statement that, “in considering the extent and timing of additional adjustments to the target range for the federal funds rate, the Committee will carefully assess incoming data, the evolving outlook and the balance of risks.”

The dissents came from Beth Hammack, president of the Cleveland Fed; Lorie Logan, who runs the Dallas Fed; and Neel Kashkari, who heads up the Minneapolis Fed. The last time there were four official dissents was on Oct. 6, 1992.

Officials gathered at an uncertain moment for the economy and for the Fed itself, as Mr. Powell prepares to step down as chair.

Negotiations to end the war in Iran appear deadlocked. The Strait of Hormuz, a crucial shipping lane for global markets, remains closed, gumming up supply chains and keeping energy prices elevated. Inflation has started to move higher, while Americans have turned more downbeat about the economic outlook.

At the same time, the Fed is on the cusp of a leadership transition. Hours before the Fed announced its rate decision on Wednesday, the Senate Banking Committee voted to advance Mr. Warsh as Mr. Trump’s nominee to replace Mr. Powell when his term ends May 15.

That leaves the Senate with roughly two weeks to confirm Mr. Warsh, who had served as a Fed governor from 2006 to 2011, as the 17th chair of the central bank.

Mr. Warsh would inherit a highly complicated economic backdrop that has prompted officials at the Fed to shelve further rate cuts for the time being. Some have even begun to make the case for the Fed to signal more directly that the next move could just as likely be a rate increase as a reduction.

In its statement on Wednesday, the Fed acknowledged the recent uptick in inflation as a result of the war in Iran and stressed that there was a “high level of uncertainty about the economic outlook.”

The concern for policymakers is that the longer the war with Iran drags on, the bigger the economic hit will be. What officials fear is a situation in which higher energy prices push up prices elsewhere, especially across the services sector, leading to a more persistent inflation problem that would be more difficult to address.

Expectations about future inflation indicate that Americans have not lost faith in the Fed’s ability to eventually bring inflation back down to its 2 percent target. But the emergence of another shock that has pushed inflation further from the Fed’s goal — the fourth in five years — will no doubt test that confidence.

The other economic risk stemming from the war is that consumers will curb other spending to cover higher energy-related expenses, undermining a pillar that is propping up the economy. One comfort is that the labor market has stabilized somewhat in recent months, with the unemployment rate steady at 4.3 percent.

Fed officials have indicated that a sharp deterioration in the labor market would prompt them to consider cutting rates again. They also need to have more tangible evidence in hand that inflation is headed back down to the Fed’s target.

As evidenced by Wednesday’s varying opinions, Mr. Warsh will face intense internal resistance if he pursues substantially lower rates, as Mr. Trump has called for since returning to the White House.

The Fed’s policy decisions are made by a 12-person committee, which also includes the six other members of the board of governors, the president of the Federal Reserve Bank of New York and a rotating set of four presidents from the 12 regional banks.

Among those who could still get a vote is Mr. Powell, whose term as governor does not end until January 2028.

Mr. Powell said on Wednesday that he would remain at the Fed as a governor once his term as chair ends.

“After my term as chair ends on May 15, I will continue to serve as a governor for a period of time to be determined,” he said, adding, “I plan to keep a low profile as a governor.”

He said his decision to stay stemmed from his concerns about the legal attacks on the Fed, including a criminal investigation by the Justice Department into cost overruns for renovations at the central bank’s headquarters in Washington and whether he lied to Congress about them.

The investigation prompted a rare public rebuke from Mr. Powell, who said it was a coercive tool to get the Fed to comply with the president’s demands for lower rates. Mr. Powell has said he would not leave the Fed until the investigation was “well and truly over, with transparency and finality.” He said he would base his decision on what is “best for the institution and for the people we serve.”

The Justice Department ended its investigation on Friday but left open the possibility of reviving it. Federal prosecutors can also appeal a federal judge’s recent ruling that quashed subpoenas issued to the central bank.

Senator Thom Tillis of North Carolina, a top Republican who had held up Mr. Warsh’s confirmation because of the investigation, suggested that any appeal would be not about pursuing Mr. Powell but defending the power of prosecutors to issue subpoenas. An appeal would only further encourage Mr. Powell to stay, however.