What is the ruling of Islamic law on communicating with a girl before marriage and agreeing to marry her, and is that considered fornication, knowing that the relationship developed into multiple meetings?

Acquaintance between foreign young men and women with the intention of marriage is a gateway to tribulation and corruption. What is legislated is engagement through the guardian. Any relationship before marriage, or seclusion (khalwa), or saying "I have given myself to you" is invalid and forbidden. A valid marriage has conditions, such as the guardian and witnesses. Therefore, this relationship must be severed, and sincere repentance must be made, by refraining from the act, regretting it, resolving not to return to it, while concealing the sin and increasing good deeds.