YA Fiction book in Ukraine

I read a book about 25 years ago (I think the book was a lot older than that but I don’t know how old ) and I think by that point it was already pretty old because it was a novel from school and I don’t remember the title but I remember the basic plot which was a boy name Nikolai his parents had died, and his granny was raising him, and she wanted him to travel to either the United States or Canada, where his aunt and his uncle had settled. In order to do that, he stole it away on a ship, and his grandmother gave him three gold nuggets that he tied in a handkerchief I believe. When he got to his aunt and uncle, his uncle was really mean to him. Eventually his grandmother was able to cross the ocean , and was reunited with him. I’m trying to find the book title and/or the author. Any help is appreciated. Thank you.