Defense Minister Itsunori Onodera plans to tell his French counterpart that Japan has strong concerns about France’s plan to sell two helicopter carriers to Russia, according to a Japanese government source.

In a move meant to show support for its ally, the United States, Onodera will tell French Defense Minister Jean-Yves Le Drian, who will visit Japan next week, that the sale of amphibious assault ships to Russia “will not be appropriate in view of the international situation” since the recent downing of a Malaysian airliner in Ukraine, the source said.

The Mistral-class warships to be sold to Russia can each carry up to 16 helicopters, four amphibious landing craft and 900 soldiers. Russia plans to deploy one in the Far East, according to the government source.

While Japan, which is aiming to conclude a peace treaty with Moscow and resolve a territorial dispute, wants to maintain good relations with Russia, a senior Defense Ministry official said deployment of the French vessel in the Far East could pose a threat to regional security.

Meanwhile, the government said Thursday it will consider imposing additional sanctions against Russia in light of the downing of the Malaysia plane in an area of Ukraine controlled by pro-Russian separatists, a government source said.

The move was endorsed at a National Security Council meeting attended by top officials, including Prime Minister Shinzo Abe, the source said.

Details of sanctions and when to invoke them will be decided after the European Union steps up its sanctions against Moscow, the source said.

Additional measures by Tokyo will likely be “limited” to contain the adverse impact they may cause on its negotiations with Russia over a territorial dispute, a Foreign Ministry source said earlier.

“If it is confirmed that pro-Russian forces in Ukraine have shot down (the Malaysian plane) using Russian-built weapons, additional sanctions will be unavoidable,” said the Foreign Ministry source.