KIEV, April 26. /TASS/. Ukraine will soon announce a tit-for-tat measure in response to Russia’s decision to expel a Ukrainian diplomat, spokesperson for the Ukrainian Foreign Ministry, Oleg Nikolenko said Monday.

"Moscow’s declaring a diplomat of the Ukrainian embassy in Moscow a persona non grata is stripped of logic and is absolutely groundless," he noted. "The Foreign Ministry will soon announce expulsion of a Russian diplomat from Ukraine on the principle of reciprocity."

He branded the expulsion of the Ukrainian embassy staffer as "another provocation against employees of Ukrainian diplomatic missions in Russia."

Earlier on Monday, the Russian Foreign Ministry said that a Ukrainian embassy staffer had been declared persona non grata; he will have to leave Russia before April 30.