US central bankers are divided over how fast they will need to raise interest rates next year, given differences over the causes behind the low inflation and wage gains seen to date, a report showed Wednesday.

The minutes of the December 12-13 policy meeting, when the Federal Reserve raised the benchmark lending rate for the third time last year, also showed officials believe the likely benefits of the recently adopted tax cut are highly uncertain.

While the tax cuts could boost spending, there are indications companies are likely to use the windfall for mergers and share buybacks, the minutes said.