Japan on Thursday raised its travel advisory for Belarus to the second-highest level to warn against visiting there, citing possible dangers after Japan imposed sanctions on the former Soviet republic for its role in Russia's military invasion of neighboring Ukraine.

The Foreign Ministry also issued a Level 2 advisory, the third-highest rating on its four-point scale, for most of Russia, including Moscow, asking Japanese citizens to refrain from nonessential travel to the areas.

For the Ukrainian border areas along Russia and Belarus, the ministry raised the advisory to Level 4, the highest rating, which urges all Japanese nationals to evacuate from the area and to not travel there, citing "the possibility of military conflicts."

"There is concern that Japanese will possibly face danger" in Belarus, following Japan's decision to join the United States and European nations in imposing sanctions on the country "due to its involvement in Russia's aggression against Ukraine," according to the ministry.

Earlier in the day, Tokyo decided to impose sanctions such as asset freezes of seven top Belarusian officials including President Aleksandr Lukashenko and stricter export control measures for Belarus, which has served as an entry point for Moscow's forces attacking Ukraine.

The ministry also said a separate sanction measure by European countries of closing off airspace to Russian and Belarusian flights could make it harder to leave the two nations.

The whole of Ukraine has already been under a Level 4 warning since mid-February, following Russia's military buildup along its borders with the country.