The Scholars have stated:

أنكحة الكفـار صحيحة يقرون عليهـا إذا أسلموا أو تحاكموا إلينا

“The marriages of the kuffar are regarded as being valid, they should be considered [as legitimate spouses] if they were to embrace Islam or were to seek judgement from us… ”

[Reference]

Translated and Answered by

AbdulFattaah bin Uthman
Abu Fajr