Kyiv (Ukraine) (AFP) - Russia on Tuesday issued a veiled warning over the future of grain exports via the Black Sea after refusing to extend a key agreement allowing safe passage for cargo ships from Ukrainian ports.

The warning came hours after Ukraine said a Russian strike overnight had damaged facilities at the southern port of Odesa, one of the main transit hubs for grain under the pact signed with the United Nations and Turkey.

“Without appropriate security guarantees, certain risks arise here (in the Black Sea),” Kremlin spokesman Dmitry Peskov said.

Were a new arrangement to allow for exports “formalised without Russia, then these risks should be taken into account”, he said.

Moscow’s invasion last year saw Ukraine’s Black Sea ports blocked by warships until the agreement – brokered by the UN and Turkey and signed in July 2022 – allowed critical grain shipments to restart.

The Kremlin said it was exiting the deal on Monday, after months of complaining that elements of the agreement allowing the export of Russian food and fertilisers had not been honoured.

President Volodymyr Zelensky on Monday said Ukraine was nonetheless prepared to keep exporting grain via the Black Sea despite Russia’s exit.

But Peskov put Moscow’s position in stark terms when he said Ukraine was using the Black Sea export corridor “for combat purposes”.

Russia later told Turkey that the coordination centre overseeing the deal would be disbanded in the wake of Moscow’s exit.

Foreign Minister Sergei Lavrov told his Turkish counterpart Hakan Fidan the decision to quit the deal also meant Russia would lift “safe navigation guarantees” for cargo ships in the Black Sea.

- Retaliation strike -

Moscow said its strike on Odesa came in retaliation for a Ukrainian attack one day earlier on the Crimea bridge, a key transit artery linking Russia’s mainland to the peninsula annexed by Moscow in 2014.

The bridge was targeted using seaborne drones by Kyiv’s navy and SBU security service, a source told AFP.

Moscow’s forces struck back against “facilities where terrorist acts against Russia had been prepared using unmanned boats”, the country’s defence ministry said in a statement.

Kyiv’s military earlier said it had destroyed six Kalibr missiles and 21 Iran-built attack drones targeted at the Odesa region, but that port facilities were damaged in an assault overnight.

“Unfortunately, the debris of the downed missiles and the blast wave from the downing damaged the port infrastructure facilities and several private homes,” Ukraine’s military southern command said in a statement.

The Odesa region is home to the maritime terminals central to the export deal between Moscow and Kyiv that has enabled the shipment of more than 32 million tonnes of Ukrainian grain over the past year.

- ‘Tough fight’ -

While Kyiv has launched a counteroffensive to punch through the Russian lines, Moscow’s forces have also sought to make their own gains.

They are pounding Kyiv’s forces close to the eastern town of Lyman, hoping to force the Ukrainians to redeploy and abandon their drive to retake captured cities such as Bakhmut.

Further to the north, the Russian military said Tuesday it had advanced 1.5 kilometres (one mile) in an area near the city of Kupiansk.

Ukraine had stockpiled Western arms ahead of the highly anticipated fight against the Russian troops, but has acknowledged slow progress and called on the United States and other allies to provide more long-range weapons and artillery.

General Mark Milley, the top US military officer, said Tuesday that Kyiv’s forces are facing heavily fortified Russian positions that include complex minefields, tank obstacles, barbed wire and trenches.

But Ukraine has “a significant amount of combat power not yet committed,” he said.

“Right now, they are preserving their combat power, and they are slowly and deliberately and steadily working their way through all these minefields, and it’s a tough fight.”