If one can assume that than they can also assume the European admixture in North Africans is from the Barbary Slave Trade.The Islamic period witnessed massive amounts of enslaved Sub-Saharan Africans enter the North African, South Asian and Middle-Eastern countries.
Before Islam, there were hardly any Blacks in North Africa, South Asia and the Middle-East. I believe Ancient Egypt was probably the Pre-Islamic nation that had the most extensive contact with SSA people(Kushites, Nilotes) through war, enslavement and trade. When Islam came, the flood gates opened for the SSA peoples.