What is the legitimate solution for a man separating from a woman with whom he fathered three children from an illicit ten-year relationship, after her refusal to come to his country for marriage, and his refusal to return to her country or send his children to him? Is it sufficient to seek forgiveness for the sin and forget the woman and children?

You must repent to Allah Almighty for the repeated crime of adultery, for it is one of the gravest sins that Allah has forbidden and threatened its perpetrator with punishment, as He Almighty said: "And do not approach unlawful sexual intercourse. Indeed, it is ever an indecency and an evil way." [Quran 17:32] And part of complete repentance is not to think of the adulteress. It is not permissible to marry her if she is a Muslim, unless she repents. If she is not a Muslim, it is not permissible to marry her due to her lack of chastity. As for the children, they are children of fornication and are not legally attributed to you. If the woman embraces Islam and her Islam is good, then it is permissible for you to marry her.