Federal Reserve Chair Janet Yellen said the U.S. economy has further to go to achieve full health and predicted small businesses will play a vital role in the recovery.

Job creation is “crucial to this process,” and small companies “are responsible for a large share” of new employment, Yellen said Thursday in Washington in the text of remarks prepared for a speech to owners of small companies and officials from the U.S. Small Business Administration.

“America has come a long way since the dark days of the financial crisis, and small businesses deserve a considerable share of the credit for the investment and hiring that have brought that progress,” Yellen said.

“Although we have come far, it is also true that we have further to go to achieve a healthy economy, and I am certain that small businesses will continue to play a critical role in reaching that objective.”

Confidence among U.S. small businesses has reached a six- year high, according to a survey of 1,699 employers by the National Federation of Independent Business. Some 28 million small businesses employ half of the private-sector workforce, according to the Small Business Administration, which guaranteed about $30 billion in loans last year.

More than half of the net number of jobs created since employment began growing in 2010 were generated by companies with fewer than 250 employees, “and most of that amount was accounted for by firms with fewer than 50 employees,” Yellen said, citing data from the Labor Department.

Pre-Recession Peak

Private employment in March exceeded the pre-recession peak for the first time as payrolls excluding government agencies rose by 202,000 workers. Private payrolls rose by 273,000 workers in April, lifting the total to 116.3 million.

SBA Administrator Maria Contreras-Sweet, who took office in April, said in a speech this week the agency will introduce organizations called “growth accelerators” at universities and nonprofits that offer entrepreneurs space, mentoring, networking, business-plan assistance, and startup capital.

“Small loans from banks remain flat,” said William C. Dudley, president of the Federal Reserve Bank of New York. Small businesses “are vital to our national and local economies,” Dudley said Thursday to a conference at the New York Fed.

Fed policy makers said last month the economy is showing signs of picking up and the job market is improving. The Federal Open Market Committee pared its monthly asset-buying to $45 billion in its fourth straight $10 billion cut and said further reductions in “measured steps” are likely. Interest rates will probably remain low until mid-2015.

Yellen, 67, became Fed chief in February after serving as the central bank’s No. 2 official.