German Chancellor Angela Merkel has stressed there is “no military solution”, after Ukraine's leader urged Nato to send ships to the Sea of Azov.
Petro Poroshenko's request came following a naval confrontation with Russia in waters off Crimea.
On Sunday, Russia opened fire on three Ukrainian ships and seized their crews in the Kerch Strait.
Mrs Merkel said the crisis was “entirely the doing of the Russian president”.
However, she said that “issues like these can only be solved by sensible dialogue”.
Russian President Vladimir Putin accused Mr Poroshenko of creating the naval “provocation” to boost his ratings ahead of 2019 elections.
President Poroshenko has implemented martial law across Ukraine's border regions for 30 days in response to the crisis.
Would Nato help Ukraine?
The North Atlantic Treaty Organisation is the world's most powerful regional defence alliance, and members agree that an armed attack against one is considered an attack against them all.
Ukraine is not a Nato member, but it is a Nato partner country, meaning they co-operate on some political and security issues.
Mr Poroshenko told Germany's Bild newspaper: “Germany is one of our closest allies and we hope that states within Nato are now ready to relocate naval ships to the Sea of Azov in order to assist Ukraine and provide…
