Case for interest rate hike is strengthening, Fed's Kaplan says

The case for an interest rate hike was strengthening, a top US central bank official.

However, in remarks to CNBC the president of Federal Reserve bank of Dallas, Robert Kaplan, refused to offer a specific timetable for the next tightening move.

Kaplan was not a voting member of the US Federal Open Market Committee, the central bank's main policy organ.