"On 17 April, Ukraine's charge d'affaires in the Russian Federation, Vasily Pokotilo, was summoned to the Russian Foreign Ministry regarding the illegal activities of the consul of the Ukrainian consulate general in St. Petersburg, who was detained on 16 April", the ministry said in a statement.
"It was announced that his [Sosoniuk's] presence in Russia is undesirable and [he was] advised to leave within 72 hours, starting 19 April", the statement added.
Oleksandr Sosoniuk, the Ukrainian consul, was detained on Saturday morning during a meeting with a Russian national who allegedly wanted to pass classified information to Ukraine.
The diplomat was held in custody for several hours, a spokesman from the Ukrainian Foreign Ministry said. Kiev said it assessed the detention as a hostile action on the part of Russia and was preparing response measures toward Russian diplomats.