In the Treaty of Buchach (1672), both the Commonwealth and the Ottoman Empire referred to the Hetmanate as the Ukrainian State in their respective languages.
The first foreign power to officially refer to Muscovy as the Tsardom of Russia was in the Grzymułtowski Treaty (1686).
Hence, in terms of international recognition, Ukraine is older than Russia.
If you disagree, please cite a treaty and provide a link to an archival scan, in which the Tsardom of Moscow is explicitly referred to as the Tsardom of Russia by a foreign power earlier than 1672.
Sources:
- Akta dotyczące stosunków Polski z Moskwą 1678–1700, p. 91.
- Pacta z Cesarzem Tureckim… Buczacz 1672, AGAD (Warsaw), facsimile on Wikimedia Commons, p. 4.
- Kołodziejczyk, D. Ottoman–Polish Diplomatic Relations… (Brill, 2000), pp. 318–322,