The US Federal Reserve has looked past a dismal reading on US economic growth and announced a cut in its bond-buying stimulus, a sign of its confidence in the economy's prospects.

The Fed said in a statement that it would reduce its monthly bond purchases to $45 billion from $55 billion, a widely expected decision that keeps it on track to end the programme as soon as October. 

The decision was unanimous.

At the end of a two-day policy meeting, the central bank said the economy "will expand at a moderate pace and labour market conditions will continue to improve gradually" – an assessment that tracked its statement last month.

Recent information "indicates that growth in economic activity has picked up recently, after having slowed sharply during the winter in part because of adverse weather conditions," the Fed said in the statement.

The Fed has now reduced its monthly bond purchases by a cumulative $40 billion in four steady steps. 

The gradual tapering seeks to close an era in which the central bank's balance sheet quadrupled to more than $4.2 trillion through three separate purchase programmes launched to battle the financial crisis and recession and the slow growth that followed.

The projected end of the programme sets the stage for a series of policy decisions expected next year on when and how to reduce the balance sheet to more usual levels, and, most notably, when to move the target interest rate above the near zero level maintained since late 2008.

Janet Yellen's second policy-setting session as Fed chair offered no new guidance on that front. 

The Fed has said it will keep the overnight target rate between 0 and 0.25% "for a considerable time" after the bond-buying programme ends – language reiterated today.

The Fed's decision to further slow its bond-buying came despite new data showing the economy grew at a disappointing 0.1% annual rate at the start of the year. 

The Fed had already said it anticipated a poor first-quarter result because of a harsh winter in many parts of the United States.

Going forward, the bond purchases will be split between $25bn of Treasuries and $20bn of mortgage-backed securities, a cut of $5bn a month to each.

Analysts expected little out of this session as the Fed's policy committee enters what may prove a sort of holding pattern as it closes out the bond purchases and debates when an initial interest rate increase may be warranted. 

Investors currently expect the first rate rise around the middle of next year.

With little sign of inflation and unemployment at a still-elevated 6.7%, Ms Yellen has said there is plenty of "slack" in the economy and a need to keep rates low.

In an April 16 speech, she said the United States may still be more than two years away from what the Fed views as the "longer-run normal unemployment rate" of between 5.2% and 5.6%.

"Thus far in the recovery and to this day, there is little question that the economy has remained far from maximum employment," she said.

While the latest report on GDP growth did not throw the Fed off course, it could influence the discussion going forward. The 0.1% annual growth rate was far below expectations.

"This certainly is going to give Janet Yellen's camp a lot more ammunition to remain on the more neutral to dovish side," Richard Cochinos, a currency strategist at Citi in New York, said ahead of the Fed's decision.

It will also focus attention on the next round of data on jobs and inflation as signs of whether what the Fed analysed as a winter lull was in fact nothing more than that.