Трябва ти нещо в този смисъл:
I, (name), residing (city), holding (type) visa, would like to invite my (friend/relative, name), for the purpose of visiting me.
During her/their visit in the United States she/they will stay with us at the address stated below. My (friend/relative) will be responsible for his own expenses while he is in the United States.
She/they may be presenting this letter to you, with other evidence to establish her/their close ties to his country, and to assure you that she/they will return prior to the expiration of her/their stay in the United States.
Your kind consideration to this request will be greatly appreciated. Please feel free to contact me.
има още идеи. Дано нещо ти свърши работа
Пожелавам ти успех!