WASHINGTON—Federal Reserve officials decided only after considerable disagreement to hold interest rates steady at their September meeting but expected to raise them “relatively soon” thereafter.

Several officials viewed the decision as a “close call,” with some wanting to move then and others preferring to wait a bit longer in hopes of seeing more improvement in the labor market, according to minutes of the Sept. 20-21 meeting, released Wednesday after the usual three-week lag.

The minutes didn’t say when the next rate increase might come, but they largely reinforced market and analyst expectations of a Fed move in December, after the U.S. presidential election. The central bank has two more policy meetings this year, in early November and mid-December.

About 74% of economists surveyed by The Wall Street Journal in September said they expected the Fed’s next move in December.

In their economic projections released last month, 14 of 17 Fed officials indicated they expected to raise rates before the end of the year. Policy makers believed they would raise their benchmark federal-funds rate “relatively soon if economic developments unfolded” about as they expected, the minutes said.