Russian Ambassador to the United Nations Vassily Nebenzia (Front) addresses a Security Council emergency meeting regarding accusations of the use of a nerve agent in the United Kingdom at the United Nations headquarters in New York, on March 14, 2018. (Xinhua/Li Muzi)

MOSCOW, March 28 (Xinhua) -- The Russian Foreign Ministry on Wednesday condemned the expulsion of Russian diplomats by Ukraine over an ex-spy poisoning case, saying that Moscow will certainly respond with harsh retaliation.

It said in a statement that the Ukrainian government took a "thoughtless" stance in the incident.

"It should also be noted that Kiev has orchestrated its moves in unison with Western nations, including France and Germany, which is creating a negative backdrop for talks on the Ukrainian settlement, including in the Normandy format," the ministry said.

It warned that Kiev's unfriendly step would be followed by a fitting and painful response from Moscow.

Ukrainian President Petro Poroshenko announced Monday that Ukraine had decided to expel 13 Russian diplomats due to the poisoning of ex-spy Sergei Skripal in Britain.