I've been to North Africa and I've met many North Africans in France, and, as far as I know, nobody has French as their native language.
The native language (and the official language) of all these countries is Arabic, together with Berber and some local dialects.
French is learnt as a second language at school, and used for international communication. Although most North Africans who have learnt French speak it fluently, there seems to be a wide variation in the level of written French. While the more educated people can write French at native level, others seem to struggle with spelling and non-audible grammar features such as verb conjugation endings and adjective agreements.