The US Federal Reserve has said that the economy has strengthened moderately but still needs stimulus measures to underpin recovery. In a statement after a two-day meeting, the Federal Reserve said it would keep its policy of buying 85 billion dollar a month of Treasury bonds and mortgage-backed securities. The Fed said it wanted to see signs of a long-term fall in unemployment. The statement said policymakers continued to see downside risks to the economic outlook. The forecast for US economic growth this year was lowered slightly with the Federal Reserve saying it expected the economy to grow by 2.3 percent to 2.8 percent this year against its December projection of 2.3 percent to 3 percent. The Fed noted that the job market had improved, consumer spending and business investment had increased and the housing market had strengthened. But it did not expect unemployment to fall to 6.5 percent from its current 7.7 percent until 2015.