Are words uttered unintentionally that a person immediately regrets and seeks forgiveness for considered major or minor sins, and what is the solution to overcome this condition?

Lying in all its forms is forbidden, and one must avoid it and strive for truthfulness. Allah Almighty says: (O you who have believed, fear Allah and be with the truthful.) The Prophet, peace and blessings be upon him, said: "Leave what makes you doubt for what does not make you doubt. For truthfulness is tranquility and lying is doubt." One can avoid lying in a permissible way, which is through tawriya (equivocation). This is when a statement has an apparent meaning that readily comes to the listener's mind, and another hidden meaning that is intended by the speaker. The aforementioned matters are considered minor sins unless they result in harm or corruption. However, persistence in minor sins or underestimating them can elevate them to major sins. The Prophet, peace and blessings be upon him, said: "Beware of the minor sins, for they accumulate upon a person until they destroy him." Therefore, you must repent.