A temporary passport
This type of passport can be delivered under exceptional circumstances. The fact of not having applied for a regular passport in due time is not considered being an exceptional circumstance.
Be also aware that the validity of a temporary passport is limited in time and space and that it is not accepted as a valid travel document by each and every country. It can, for example, not be used for travelling into the United States, not even for transiting in a US airport. First check with the embassy or the consulate of the country of your destination whether its authorities accept the Belgian temporary passport and under which conditions. Click here to find preliminary information on this subject.