According to the Hajun monitoring service on Telegram, at least 20 Belarusian tanks are being moved to a training area near Grodno - close to the Polish and Lithuanian borders.
Other Belarusian units are also undergoing a “combat readiness check”. On 13 December, Belarus' Ministry of Defence announced the "check".
On October 11, Ukraine's President Zelensky asked the G7 to monitor the Belarus-Ukraine border out of concern for Belarus' increasing involvement.
Sources: The New Voice of Ukraine, Rzeczpospolita, The Guardian
pt