FEATURE | The high-risk Black Sea escalation testing NATO like never before

Zelenskiy warns of food crisis

Last week's attack took place as the defence ministers and military chiefs of Romania, Bulgaria and fellow NATO littoral state Turkey met in Sofia to discuss the situation.

The defence minister of Turkey, which is waiting for a response from Moscow and Kyiv on a narrow maritime ceasefire proposal, used the meeting to warn Russia and Ukraine against further attacks.

Turkey controls the transit of warships through the Bosphorus and Dardanelles under the Montreux Convention.

Several countries, including Egypt, Turkey and India, have pushed for maritime ceasefires to avert fallout from the disruption of shipping at a time when global fuel and grain prices have soared.

US Secretary of State Marco Rubio said on Saturday there was growing international interest in a limited ceasefire.

Russia has rejected the idea of a narrow maritime ceasefire that it says would provide respite to Kyiv. Ukrainian President Volodymyr Zelenskiy has sounded the alarm.

"Everyone is talking about diesel and forgetting about grain. In a month or two, everyone will start talking about an agricultural crisis," he said last month.

(Reporting by Tom Balmforth in London and Luiza Ilie in Bucharest; Additional reporting by Pavel Polityuk, Gergely Szakacs, Gleb Stolyarov, Edward Carron and Michael Jones; Editing by Mike Collett-White and Alison Williams)