Actually, a distinct material culture has existed there for at least 5000 years from the 3rd (or 5th??) century BCE. And, the area has had human habitation for over 33,000 years. Before there was a Rus state, in the 9th century, there was a Slavic culture as early as the 3rd century in that region separate from what became Russia. There were also Celtic tribes there in the Iron Age. Additionally, the largest area was Iranian Sythian culture from around 10th century BCE; the remainder of what is now Ukraine was inhabited by Uralian and Turkic tribes.