The Foreign Ministry on Friday advised Japanese citizens in Ukraine to leave the European country immediately as Russia amasses troops on the Ukrainian border.
The ministry raised its travel warning for Ukraine to the highest level, which urges all Japanese nationals to evacuate from the country and avoid traveling there "regardless of purposes."
The advisory cited the recent start of a Russia-Belarus joint military exercise in Belarus, which borders Ukraine, as well as a new batch of Russian military vessels seen in the Black Sea.
"There is an increasing possibility that the situation could rapidly deteriorate," the ministry said in the statement.
There are about 150 Japanese citizens in Ukraine, a foreign ministry official said.