The latest Federal Open Market Committee September meeting minutes revealed that some Fed officials were staying cautious of the weakness of economic growth in China and the euro-zone, a new Capital Economics report said.

This alongside the dollar's recent appreciation is causing Fed officials to be more concerned of the potential negative impact on U.S. exports and leave inflation below the Fed's 2% target for longer.

The FOMC stood by its pledge that the first rate hike would occur a "considerable time" after the Fed had stopped buying assets.

“Several FOMC participants worried it implied a longer period before liftoff than they envisaged, while some worried that it would be misunderstood as a calendar-based commitment rather than data dependent,” the report said.

“Crucially, most participants wanted to "clarify" the forward guidance so it was more closely linked to their assessment of the progress being made in achieving maximum employment and the 2% inflation target,” it continued.

But despite the news, Capital Economics noted that there is little in the minutes to changes its view that the first rate hike will be as soon as march 2015.

In the September meeting, the FOMC announced plans to add to its holdings of agency mortgage-backed securities at a pace of $5 billion per month rather than $10 billion per month, and to add to its holdings of longer-term Treasury securities at a pace of $10 billion per month rather than $15 billion per month.