Ukraine`s president Petro Poroshenko (2nd R) meets with servicemen as he visits the 169th training centre `Desna` of the Ukrainian Army ground forces in Chernihiv Region, Ukraine on 28 November 2018. Photo: ReutersUkraine president Petro Poroshenko accused Russia’s Vladimir Putin of seeking to annex his entire country and called in interviews with German media for Chancellor Angela Merkel to come to Kiev’s aid in the crisis.Russia seized three Ukrainian navy ships and their crews on Sunday near the Crimean peninsula, which Moscow annexed in 2014, over what it said was their illegal entry into Russian waters – a charge Ukraine strongly refutes.In interviews with Germany’s Bild newspaper and the Funke newspaper group on Thursday, Poroshenko rejected Russia’s charge that the vessels’ entry into the Azov Sea – a body of water shared by Ukraine and Russia on which the Ukrainian ports of Mariupol and Berdyansk sit – was a provocation.”Don’t believe Putin’s lies,” he told Bild, Germany’s biggest-selling paper, comparing Russia’s protestations of innocence in the affair to Moscow’s 2014 denial that it had soldiers in Crimea even as they moved to annex it.”Putin wants the old Russian empire back,” he said. “Crimea, Donbass, the whole country. As Russian Tsar, as he sees himself, his empire can’t function without Ukraine. He sees us as his colony.”The seizure of the navy vessels drove tensions to their highest since 2015, when Moscow-backed rebels rose against the Kiev government in the eastern Donbass region, sparking a war that has killed tens of thousands.Poroshenko called on Germany, the largest and wealthiest buyer of Moscow’s gas exports, to halt the building of an undersea gas pipeline that would allow Russia to supply Germany directly, cutting out Ukraine.”We need a strong, resolute and clear reaction to Russia’s aggressive behaviour,” he told Funke. “That also means stopping the Nord Stream 2 gas pipeline project.”Germany regards the pipeline, which is being built by Russian state-owned energy company Gazprom, as a private investment. But Merkel recently acknowledged its “political dimensions” and said Ukraine must continue to be a conduit for Russian gas sold to western Europe.German officials said on Wednesday that their position on the pipeline remained unchanged and that talk of tighter sanctions against Moscow, demanded by the United States and many European politicians, was “premature”.Poroshenko also called for the stationing of NATO vessels in the Sea of Azov.