"Russian Foreign Minister Sergey Lavrov has said that Russia will consider the transfer of F-16 fighter jets to Ukraine as a threat from the West in the nuclear sphere.
Source: Lavrov in an interview with Lenta.ru
Details: The Russian minister has stated that the very fact of the appearance of F-16 fighter jets in Ukraine will be considered "a threat in the nuclear sphere".
According to him, F-16 fighter modifications have a base on which nuclear weapons can be fixed."
https://www.yahoo.com/news/russia-consider-f-16s-transfer-014708545.html