Armenia has formally joined the international criminal court (ICC), officials said, a move which traditional ally Moscow has denounced as unfriendly. The Hague-based court in March issued an arrest warrant for the Russian president, Vladimir Putin, over the war in Ukraine and the illegal deportation of children to Russia. Yerevan is now obliged to arrest the Russian leader if he sets foot on its territory. “ICC Rome statute officially entered into force for Armenia on 1 February,” the country’s official representative for international legal matters, Yeghishe Kirakosyan, told AFP. The Kremlin spokesperson Dmitry Peskov said Armenia had taken a “wrong decision” when its parliament voted in October to ratify the ICC’s Rome statute, and the Russian foreign ministry has called the move an “unfriendly step”. Armenia is home to a permanent Russian military base and is part of the Moscow-led military alliance the Collective Security Treaty Organisation (CSTO), that consists of several ex-Soviet republics. Western countries hailed the ratification, which marks the expansion of the court’s jurisdiction into what was long seen as Russia’s back yard. “The world is getting smaller for the autocrat in the Kremlin,” the European Commission president, Ursula von der Leyen, said in reference to Putin after Armenia ratified the ICC statute in October. Armenia’s prime minister, Nikol Pashinyan, has tried to reassure Russia that his country is only addressing what it says are war crimes committed by its neighbour, Azerbaijan, in their long-running conflict, and is not aiming at Moscow. Kirakosyan said: “Joining the ICC gives Armenia serious tools to prevent war crimes and crimes against humanity on its territory. “First of all, this concerns Azerbaijan,” he added. Yerevan has fought two wars with its arch-foe over the disputed Nagorno-Karabakh region. But Armenia’s move illustrated a growing divide between Moscow and Yerevan, which has grown angry with the Kremlin’s perceived inaction over Azerbaijan’s belligerence. In September Azerbaijani forces swept through Karabakh – where Russian peacekeepers are deployed – and secured the surrender of Armenian separatist forces that had controlled the mountainous region for decades. “Armenia hoped that by joining the ICC, by making such a sensitive step for Russia, it could receive security guarantees from the west,” independent analyst Vigen Hakobyan told AFP. “But apparently it has strained its Russia ties without receiving real security guarantees from the west.” Armenia signed the Rome statute in 1999, but did not ratify it, citing contradictions with the country’s constitution. The constitutional court said in March those obstacles had been removed after Armenia’s adoption of a new constitution in 2015. Last November, Yerevan formally deposited its instrument of ratification of the Rome statute.