Ukraine made its first shipment of grain since Russia’s invasion, marking a small but crucial first step toward unlocking the millions of tons of crops piling up in the country and boosting global food supplies.

The Razoni, a cargo ship loaded with 26,527 tons of corn, left for Lebanon on Monday morning, according to the United Nations, which together with Turkey helped broker the deal to restart exports. Ukraine Infrastructure Minister Oleksandr Kubrakov confirmed the departure and said there were 16 other ships in the greater Odesa region waiting for their turn to sail.

Wheat, corn and soybean futures slid in Chicago. Ukraine is one of the biggest grain and vegetable-oil suppliers and the loss of exports via its Black Sea ports has shaken the food trade and raised the threat of a hunger crisis. Monday’s shipment represents a milestone achievement under the July 22 agreement to create safe shipping corridors through three of Ukraine’s ports, although it remains unclear how quickly exports can ramp up.

The Razoni, a cargo ship loaded with 26,527 tons of corn, left for Lebanon on Monday morning.

“Ensuring that existing grain and foodstuffs can move to global markets is a humanitarian imperative,” a spokesman for UN Secretary-General Antonio Guterres said in a statement. “The secretary-general hopes that this will be the first of many commercial ships moving in accordance with the initiative.”

Scores of ships are stuck in the ports dotted along the Black Sea and are expected to begin moving out in “caravans” if all goes well. However, shipowners will have to secure insurance for cargoes and vessels, and also find enough crew to sail them. A Russian attack on Odesa’s sea port with cruise missiles hours after signing the deal raised questions earlier about its commitment.

Ukraine will start moving agricultural goods to ports this week, Kubrakov said on TV. The country has been shipping some volumes of grain by road and rail while the ports remained closed, but in much smaller volumes than it can export by sea. It expects to reach full throughput capacity for transporting agricultural goods within weeks, the minister wrote earlier.

The pace of exports will be important as Ukraine’s farmers have warned they are running out of space to store crops, which could have a negative effect on how much grain is sown for next year’s harvest. 

Ukraine has also accused Russia of stealing grain from occupied areas of the country and exporting it. Lebanon seized a ship loaded with barley and wheat flour while it determines whether the cargo may have been stolen from Ukraine, Public Prosecutor Ghassan Oueidat said at the weekend. Grain shipments from Russian-occupied Crimea have surged since the invasion, indicating that Ukrainian grain is being exported via sanctioned ports there, according to analysts. Russia denies stealing grain.

The Razoni is expected to arrive in Istanbul on Tuesday, according to Turkey’s Defence Ministry. The agreement provided for monitoring by a joint coordination center in Istanbul, with representatives of all the parties. 

The World Food Programme is planning to purchase, load and ship an initial 30,000 tons of wheat out of Ukraine on a UN-chartered vessel, with more details expected in the coming days, the UN said.