ISTANBUL, TURKEY — Less than 24 hours after Russia and Ukraine struck a deal to allow grain to be shipped out of Ukrainian Black Sea ports, two Russian missiles struck the Port of Odesa on July 23, casting doubt on the long-term viability of the agreement.

The Ukrainian military said two missiles fired from Russian warships hit the area of a pumping station at the port and two others were shot down by air defense forces, according to Reuters.

Ukraine President Volodymyr Zelenskiy denounced the attack as “barbarism,” while the Russian government said it had only targeted military infrastructure at the port and that it would not impact Ukraine’s ability to export grain, according to Reuters.

The Ukraine government said they would continue preparations to export grain from the Port of Odesa despite the attack.

The plan, according to a recent report by Reuters, includes Ukrainian vessels guiding grain ships through mined port waters, with Turkey overseeing inspections of ships to allay Russian concerns they might smuggle weapons to Ukraine.

If executed, the deal, brokered by the United Nations and Turkish President Recep Erdogan, would enable Ukraine, one of the world’s biggest wheat and corn producers and exporters, to move millions of tonnes of grain on to the world market through its major Black Sea ports.

Although Ukraine has been able to transport several million tonnes of grain via rail, rivers and roadways, it is estimated that more than 20 million tonnes of grain that would have been exported has remained in Ukraine.

The result of the port blockade has been record-high grain prices and a sharp increase in food insecurity, particularly in the Middle East and Africa, which depend heavily on wheat imports from the Black Sea region.

Wheat futures on the Chicago Board of Trade rose nearly 4% to $7.86 a bushel on July 25, regaining much of the ground lost after the agreement was announced.

Even if the agreement holds and grain ships are allowed to flow freely in and out of Ukrainian ports, there is still concern that the war, now in its fifth month, will severely impact Ukraine’s ability to harvest its current crop.

With farmers struggling to complete their harvest, particularly in the war-torn sections of Ukraine, and with reports of Russian troops setting fire to Ukrainian wheat fields, agricultural agencies are forecasting that the country’s grain output will be significantly smaller than usual in 2022-23.

For instance, the US Department of Agriculture’s Foreign Agricultural Service projects Ukraine’s 2022-23 wheat crop at 19.5 million tonnes, well below last year’s 33 million and, if realized, the smallest in 10 years.