Ukraine has banned Russian adult men aged 16 to 60 from entering Ukraine, the head of the border service Petro Tsygykal said in a televised meeting today.
"Today, the entry of foreigners is limited - primarily citizens of the Russian Federation - non-admission of citizens of the Russian Federation aged from 16 to 60, male," Mr Tsygykal said.
Ukraine imposed martial law this week, citing fears that Russia was planning a full scale invasion after Russian vessels fired on and captured Ukrainian ships last weekend.
US President Donald Trump on Thursday canceled his planned meeting with Russian President Vladimir Putin, two days before they were scheduled to meet on the sidelines of the G20 summit.
The US President blamed the cancellation on Russia's refusal to release Ukrainian Navy ships and sailors seized during a maritime confrontation between the two countries on Sunday.