The first shipment of Ukrainian grain since Russia's February 24 invasion leaves the port of Odessa under a UN-Turkey brokered deal to lift Moscow's naval blockade in the Black Sea.

Officials say the Sierra Leone-registered Razoni cargo ship is making its way to Lebanon through a specially cleared corridor in the heavily mined waters of the Black Sea with 26,000 tonnes of maize on board.

UN chief Antonio Guterres says he hopes "this will bring much-needed stability and relief to global food security, especially in the most fragile humanitarian contexts" while Kyiv echoes it will bring "relief for the world" if Moscow holds up its side of the accord.

Ukraine is one of the world's biggest grain exporters. The five-month blockade of its ports by Russian forces contributed to soaring food prices, hitting the world's poorest nations especially hard.

The European Union and NATO welcome the grain shipment's departure as a "first step" towards easing the food crisis.

EU spokesman Peter Stano, however, cautions the bloc still expects the "implementation of the whole deal and resumption of Ukrainian exports to the customers around the world."

He points out that Russia fired missiles at the port of Odessa on the day after the landmark deal was signed in Istanbul in late July.

NATO Secretary General Jens Stoltenberg says Western allies "strongly support the full implementation of the deal to ease the global food crisis caused by Russia's war in Ukraine".

In Moscow, Kremlin spokesman Dmitry Peskov describes the shipment as "very positive".

Ukrainian forces have recaptured 46 settlements in the key southern region of Kherson, as Kyiv looks to retake the Russian-held area, the local governor Dmytro Butriy tells national TV.

Moscow seized almost all the territory of the economically and strategically important region bordering the annexed Crimea peninsula during the first days of its invasion.

But in recent weeks, the Ukrainian army, bolstered by deliveries of Western-supplied long-range artillery, have sought to stage a counter-offensive in the area.

In late July, a Ukrainian official vowed that the Kherson region would be recaptured by Kyiv's forces by September.

The governor of nearby Mykolaiv meanwhile says that three people were injured in the city in "massive" Russian shelling overnight that damaged homes and humanitarian supplies.

In the east, which has been the main focus of Russia's onslaught, the head of the industrial Donetsk region, Pavlo Kyrylenko, says Russian shelling over the past 24 hours has killed three people.

Russia says it is blacklisting 39 British citizens, including leader of the main opposition Labour Party, Keir Starmer, and former prime minister David Cameron.

The foreign ministry in Moscow says the listed UK citizens, who also include journalists, "contribute to the hostile course of London aimed at the demonisation of our country and its international isolation".

Russia had already blacklisted Prime Minister Boris Johnson and several members of his cabinet, as well as scores of British MPs, defence officials and journalists.