Kyiv, Ukraine - Ukraine said Friday it would only sign an agreement to unblock its grain exports with Turkey and the United Nations, shunning Russia, as delegations gathered in Istanbul to relieve a global food crisis.

Moscow and Kyiv are expected later Friday to decide a mechanism to allow Ukraine to export its stockpiling grain even as Russian forces launch deadly artillery barrages over east Ukraine.

But Ukraine presidential aide Mykhaylo Podolyak excluded a deal directly with Russia, saying Kyiv and Moscow would arrive at “mirror” accords.

“We sign an agreement with Turkey and the UN and undertake obligations to them. Russia signs a mirror agreement with Turkey and the UN,” he wrote on Twitter.

He cautioned that Russian breaches of the deal and incursions around Ukraine’s ports would be met with “an immediate military response”.

The first major accord between the warring sides -- brokered with the UN and Turkey -- was expected while Russian forces battered Ukraine’s southern coast and left several dead in the industrial Donbas. President Recep Tayyip Erdogan’s spokesman Ibrahim Kalin announced the accord would be signed at the lavish Dolmabahce Palace on the Bosphorus Strait with UN Secretary-General Antonio Guterres and the Turkish leader.

Deal offers ‘some hope’

But the deal drew scepticism from Ukrainian farmers under pressure in the war-battered south to shift stores from rapidly-filling silos and with local prices tanking.

“It gives some hope but you can’t believe what the Russians say,” said Mykola Zaverukha, a farmer with some 13,000 tonnes of grain waiting for export.

“Russia is unreliable, they have shown themselves to be year after year,” he told AFP in the southern Mykolaiv region.

The Kremlin said meanwhile it was “very important” the parties arrived at an understanding.

“It is very important to unblock supplies of fertilisers, foodstuffs and grain to the world markets,” spokesman Dmitry Peskov told reporters.

Despite hopes for a breakthrough, Russian forces pursued a relentless shelling campaign in the eastern Donetsk region, which has been the focus of Russia’s campaign in recent months.

“Five killed and 10 wounded in the region in the last 24 hours,” the Ukrainian presidency announced Friday.

In the Donetsk village of Chasiv Yar, which was hit by a strike on July 10 that killed more than 45 people, a 64-year-old woman gathered apricots near the wreckage.

“There is nothing anymore. The officials have left. We have to fend for ourselves to stay alive,” said Lyudmila, who only gave her first name.

In the south, Ukraine said Russian forces were shelling villages along the frontline in the Kherson area, where Kyiv’s army is trying to claw back Moscow-occupied territory.

‘Weaponising food’

The five-month war is being fought across one of Europe’s most fertile regions by two of the world’s biggest grain producers. Up to 25 million tonnes of wheat and other grain have been blocked in Ukrainian ports by Russian warships and landmines Kyiv has laid to avert a feared amphibious assault.

Ukrainian foreign ministry spokesman Oleg Nikolenko told AFP late Thursday that Kyiv would only accept solutions that guarantee the security of its southern regions, the position of its forces in the Black Sea and the safe export of agricultural products.