KIEV, March 26 (Xinhua) -- Ukraine will expel 13 Russian diplomats due to the poisoning of ex-spy Sergei Skripal in Britain, Ukrainian President Petro Poroshenko said Monday.

"In a spirit of solidarity with our British partners and transatlantic allies, as well as in coordination with EU countries, we decided to expel 13 of the remaining few Russian diplomats from the Ukrainian territory," Poroshenko said in a statement on its website.

While commenting on Ukraine's gesture, Kremlin spokesman Dmitry Peskov said it will be followed by a mirror response from Russia.

Former spy Sergei Skripal, 66, and his daughter Yulia, 33, are in a critical condition in hospital after being allegedly exposed to a nerve agent earlier this month.

Britain claims they were exposed to a nerve agent and holds Russia responsible. The Russian government has denied any involvement in the incident.

Following the incident, Britain expelled 23 Russian diplomats.