BRUSSELS — The European Union spent 20 million euros last year in Eritrea, hoping to help stem an exodus from the repressive African country, which is consistently one of its biggest sources of asylum seekers.

The money, about $22 million, bought equipment and materials to build a road, a seemingly uncontroversial task. The catch? Many workers on the construction site are forced conscripts, and the European Union has no real means of monitoring the project.

The decision caused outrage in human-rights circles. But that did not stop the bloc in December from deciding to give Eritrea tens of millions more, funding a system of forced conscription that the United Nations has described as “tantamount to enslavement.”

The additional aid, of €95 million, has not been previously reported, and is a jarring example of the quandary facing the European Union as it scrambles to drastically curb migration.