If the demand for workers is not sufficient due to the lack of working positions. A government could subsidize firms based on the new job opportunity creation, or they could reduce tax on new workers. This would work but there is a lost opportunity cost when government funds are used. This type of solution would affect mainly real-wage unemployment.
If workers are not willing to work. There are certain reasons why they do not want to really find work. however usually it is due to the fact that they have not had a job for a really long time. Usually a period of more then 6 months. If companies were subsidized to provide training. Or if there were government sponsored training facilities were the unemployed might learn the skills required to find a job in the shifting job market. This would mainly affect structural unemployment.