WASHINGTON (AP) -- Federal Reserve Chairman Alan Greenspan joined Labor Secretary Alexis Herman on Tuesday in a call for better job training and recruitment programs to satisfy a shortage of skilled workers.

With unemployment near 4 percent, the lowest in three decades, U.S. jobs are plentiful and some companies report having trouble finding qualified workers to fill positions. However, many unskilled workers are still encountering barriers to finding a job -- or one with good wages and benefits.Despite prosperous times, about 6 million Americans remain unemployed, 3 million part-time workers would prefer full-time jobs, and another 4 million people say they would seek jobs if not for impediments such as lack of transportation and child care, according to the Labor Department.