(Bloomberg) -- Ukraine is holding tough talks to ensure grain continues flowing from its Black Sea ports even after a deal on such exports expires next month, a key adviser said.

“We hope for a prolongation of the mandate to bring grain out of Ukraine’s ports,” Mykhailo Podolyak, an adviser to the Ukrainian president’s chief of staff said, said in a Bloomberg TV interview on Tuesday.

He declined to elaborate on when any results can be expected, describing the talks as “complicated.” Ukraine doesn’t negotiate with Russia directly, according to Podolyak. Instead, there are sub-negotiating groups that also include Turkey and the United Nations.

Ukraine has exported almost 6 million tons of grain and foodstuffs from Black Sea ports through a corridor that opened in early August, according to UN data. The country used to ship most of its grain via sea routes before the Russian forces blocked its ports at the start of the invasion in February.

Buoyed by the recent advances in its counteroffensive, Ukraine believes the war with Russia could end within months and not years, Podolyak said, adding that more weapons shipments from the West could bring a conclusion even sooner.  

Russia has failed to achieve a quick victory in Ukraine, whose troops are keeping up their surprisingly strong counteroffensive, liberating swaths of areas along the front line over the past weeks. While Western aid continues to boost the country’s military, some have called for a settlement with Russia to avoid a further deterioration. 

Tesla co-founder Elon Musk caused a media storm on Monday after suggesting on Twitter that Ukraine should seek a negotiated solution to the war and cede Crimea to Russia for good. 

Podolyak ruled out peace talks with Russia until it suffers a heavy defeat. Otherwise the Kremlin won’t be held responsible for war crimes or pay for losses, while Russia will see an increase in revanchist sentiment, emboldening it to exert even more pressure on neighbors, he said.

“We would get an endless war that will keep swallowing parts of Ukraine,” Podolyak said.

So far, Ukraine has lost about 10,000 soldiers in the war, with roughly the same number wounded, he said without giving a specific number. 

While he “wouldn’t exaggerate” the risks of Russia using nuclear weapons, Podolyak urged foreign partners to “pressure” the Kremlin to adhere to commitments to avoid such a conflict even as it’s “systemically losing” the war in Ukraine. 

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