WASHINGTON — The Federal Reserve on Wednesday stood by its efforts to keep borrowing costs at record lows, saying it isn’t yet convinced that the US economy’s growth can accelerate without significant help from the central bank.
It wants to see sustained improvement.
Fed officials reinforced their plan to keep short-term interest rates at rock-bottom levels at least until unemployment falls to 6.5 percent.
An unemployment rate of 6.5 percent is a threshold, not a ‘‘trigger,’’ for a possible rate increase, chairman Ben Bernanke said.
‘‘We are seeing improvement,’’ he said. ‘‘One thing we would need is to see this is not temporary improvement.’’
The Fed will continue buying $85 billion a month in bonds indefinitely to keep long-term borrowing costs down. Bernanke said the Fed might vary the size of its monthly purchases depending on whether the job market improves and by how much.
The unemployment rate has fallen to a four-year low of 7.7 percent, among many signs of a healthier economy.
Investors seemed pleased with the Fed’s decision to maintain its low-rate policies for now. The Dow Jones industrial average closed up about 56 points.
The Fed’s statement took note of the global stresses that have been intensified by turmoil in Cyprus, which is trying to stave off financial ruin. No longer does the Fed statement say, as it did in January, that ‘‘strains in global financial markets have eased somewhat.’’
Bernanke was asked at a news conference whether the flare-up in Cyprus signals that the US financial system might be more vulnerable than bank stress tests have shown. He sought to downplay the dangers posed by the tiny Mediterranean nation.
‘‘At this point,’’ Bernanke said, he sees no major risks to the American financial system or economy.
In its statement, the Fed noted that the US job market has improved, consumer spending and business investment have increased, and the housing market has strengthened. But its latest economic forecasts, also released Wednesday, show that the Fed still doesn’t expect unemployment to reach 6.5 percent until 2015.
The Fed also cautioned that government spending cuts and tax increases could slow the economy. It predicts that growth won’t exceed 2.8 percent this year.
A total of 13 Fed officials still think the first rate increase won’t occur until 2015, the same number that thought so in December. One official thinks the first boost won’t occur until 2016.
The statement was approved on an 11-to-1 vote.
Esther George, president of the Kansas City regional Fed bank, dissented for a second straight meeting. She reiterated her concerns that the Fed’s aggressive stimulus could heighten the risk of inflation and financial instability — a concern shared by other critics.
And while the Fed’s low interest-rate policies are intended to boost borrowing, spending, and stock prices, they also hurt millions of retirees and others who depend on income from savings.