Federal Reserve officials are considering whether to signal a new wait-and-see approach after a likely interest-rate increase at their meeting in December, which could slow down the pace of rate increases next year.

Officials still think the broad direction of short-term interest rates will be higher in 2019, according to recent interviews and public statements. But as they push up their benchmark, they are becoming less sure how fast they will need to act or how far they will need to go, and they want to assess how the economy...