Ukraine’s Air Force said it had intercepted 23 Shahed drones during the night, mostly in Odesa and Kyiv.
All 10 drones directed at Kyiv were intercepted, said Serhii Popko, head of the city administration.
Loud explosions were heard overnight as air defence systems were activated. Debris from felled drones hit three districts of the capital, damaging a non-residential building, Mr Popko said.
The Ukrainian army said it also repelled Iranian-made Shahed-136 drones launched from the Sea of Azov across the Black Sea aimed at the Odesa region.
But the attack resulted in damage to a grain elevator and a fire at facilities used to transport the country's grain exports.
Almost 40,000 tonnes of grain were destroyed, said Oleksandr Kubrakov, Vice Prime Minister for the Restoration of Ukraine and Minister for Communities and Territories Development and Infrastructure.
“The Russians attacked warehouses and grain elevators – almost 40,000 tonnes grain were damaged, which was expected by the countries of Africa, China, and Israel,” he wrote on X, formerly known as Twitter.
“The world must resist. Attacks on Ukrainian ports are a threat to the world. We can defend ourselves, and our air defence forces can use weapons effectively. We need more of it. Each air defence system saved a life. Speed and determination are the destiny of the strong ones.”
Operational Command South said the port and industrial infrastructure of the region was the “obvious target”.
“Air defence forces worked non-stop for almost three hours,” it wrote on Telegram.
Regional governor Oleg Kiper said there were no reports of casualties.
“As a result of the attack, fires broke out at the facilities of the port and industrial infrastructure of the region, and an elevator was damaged,” he said.
Mr Zelenskyy said the attacks showed Russia was intent on creating a “global catastrophe” by trying to affect food markets, prices and supplies.
“For the Russian state, this is not just a battle against our freedom and against our country,” Mr Zelenskyy said in his nightly video address.
“Moscow is waging a battle for a global catastrophe. In their madness, they need world food markets to collapse, they need a price crisis, they need disruptions in supplies.”
The attacks came as Turkey's President Recep Tayyip Erdogan told his Russian counterpart Vladimir Putin in a phone call on Wednesday that he would continue to engage in diplomacy to reinstate the Black Sea grain initiative.
Mr Erdogan and Mr Putin agreed on the Russian president paying a visit to Turkey, the Turkish presidency's statement said.
“President Erdogan expressed the importance of refraining from steps that could escalate tensions during the Russia-Ukraine war, emphasising the significance of the Black Sea initiative, which he described as a bridge of peace,” the statement added.
Russia has been pounding Odesa, a centuries-old city and one of Ukraine's main ports, since Moscow withdrew from the grain deal last month.
The agreement, brokered by the UN and Turkey a year ago, had allowed Ukraine to keep exports flowing through its deepwater ports on the Black Sea to ease a global food crisis.
Russia quit the deal on July 17, complaining that sanctions on its own grain and fertiliser exports had not been eased, and warned that ships heading to Ukrainian seaports could be considered military targets.
As a result of the deal's collapse Ukrainian grain exports in July were down 40 per cent from June, analysts said on Tuesday.
Formerly obscure ports, Izmail and Reni, have become crucial to global food supplies and are struggling to process all the grain, causing a massive bottleneck.
The Danube River port of Izmail is now the main export route for Ukrainian agricultural products.
But these ports have also become targets.
In late July, Russian drones targeted Izmail, destroying a grain warehouse.
And on Sunday, Ukrainian media reported several foreign cargo ships had arrived at the port from the Black Sea for the first time since the expiration of the grain deal.
Last week, Kyiv said it lacks the means to defend itself against strikes on its grain infrastructure carried out by Russia, which is blocking “virtually all” Ukrainian ports, according to an army spokeswoman.
The attacks come a day after Russia said it downed a wave of Ukrainian drones aimed at Moscow, Crimea and vessels in the Black Sea. A skyscraper in Moscow's financial district was struck for the second time in days.
On Monday, Russia said it would intensify its strikes on Ukrainian military infrastructure in response to drone attacks on its territory, which it has blamed on Kyiv.