Russian forces attacked Ukrainian port facilities on the Danube River used for food exports on Sunday, a day before Russian President Vladimir Putin is expected to discuss reviving a grain export deal with Turkish President Recep Tayyip Erdogan.
At least two people were injured in the strikes, a regional military spokesman said. Port infrastructure was hit, causing a fire that was quickly extinguished.
Ukraine's Air Force said 25 drones were used in overnight attacks on the Odesa region, 22 of which were shot down.
Russia's Ministry of Defense said in a statement that it was targeting fuel storage facilities in the Ukrainian port of Reni used to supply Ukraine's military. The Russian statement added that the attack was successful, with "all assigned targets neutralized."
The salvo hit just across the border from NATO member Romania, drawing a swift rebuke from the country. Romania's Ministry of Defense condemned the attack "in the strongest possible terms," calling it "unjustified and in deep contradiction with the rules of international humanitarian law."
The ministry said that there was no direct threat to Romania territory or its territorial waters.
An aide to Ukrainian President Volodymyr Zelensky accused the Kremlin of trying to create a "food crisis" with the attacks.
"Russian terrorists continue to attack port infrastructure in the hope that they will be able to provoke a food crisis and famine in the world,"the aide, Andriy Yermak, said on the messaging app Telegram.
The overnight airstrikes are the latest attempt by Moscow to target Ukrainian shipping infrastructure since July, when Russia pulled out of a deal that allowed Ukrainian ships to bypass a Russian blockade of Ukrainian Black Sea ports and navigate safe passage through the waterway to Turkey's Bosphorus Strait in order to reach global markets.
The accord's collapse pushed up global food prices and fueled fears that the world's poorest countries would struggle to feed their populations.
Erdogan, whose country effectively controls access in and out of the Black Sea, helped broker the initial deal and has taken on a role as mediator as he attempts to get Russia to rejoin. He will likely to discuss reviving the deal while meeting with Putin in the Black Sea resort city of Sochi on Monday.
Russian Foreign Minister Sergey Lavrov said his country will be ready to rejoin the pact as soon as it sees guarantees that benefits promised to Russia will be implemented.
In the interim, Ukraine has attempted to create a temporary shipping corridors for merchant ships, but Kyiv has not been able able to guarantee their safety from Russian attacks or mines. Several vessels have employed these routes despite the risk.
The UN has been seeking to revive the deal as well.