Russia is warning that limited martial law to be imposed in parts of Ukraine on Wednesday could escalate the conflict.
Twelve Ukrainian sailors captured by Russia during Sunday's confrontation in the Black Sea have been sentenced to two months in prison.
A court in Russian-controlled Crimea has accused them of illegally entering its territorial waters.
Russian forces opened fire on three Ukrainian ships and then seized them on Sunday.
Ukraine's government has declared martial law in response. Al Jazeera's Andrew Simmons reports from Kiev. - Subscribe to our channel: http://aje.io/AJSubscribe - Follow us on Twitter: https://twitter.com/AJEnglish - Find us on Facebook: https://www.facebook.com/aljazeera - Check our website: https://www.aljazeera.com/ #Ukraine #Russia #Crimea