Farmers use harvesting vehicles to harvest grain in Stavropol Krai, one of Russia’s most important agricultural lands is seen in Stavropol, Russia on July 16, 2023.Anadolu Agency | Anadolu Agency | Getty ImagesRussia’s withdrawal from a critically important wartime deal that allowed the export of Ukrainian grain across the Black Sea has reignited fears about global food security, with analysts describing the initiative’s demise as both an inevitable setback and a blow to markets.Hours before the agreement’s expiry, Russia said Monday that it would not renew the Black Sea Grain Initiative.The agreement, which was brokered by Turkey and the United Nations in July last year following Moscow’s full-scale invasion of Ukraine, was a rare diplomatic breakthrough designed to avert a global food crisis.”Today is the last day of the Grain deal,” Kremlin Dmitry Peskov said. “When the respective parts for Russia’s benefit are fulfilled, Russia will return to the deal.”The Black Sea Grain Initiative has been repeatedly elongated in short increments, amid increasing discontent from Russia over perceived restrictions that limit the full dispatch of its own grain and fertilizer exports.Russian President Vladimir Putin reiterated these complaints over a weekend call with South African President Cyril Ramaphosa, saying — according to a Google-translated report from the Kremlin — that the key objective of supplying grain to countries in need, including those on the African continent, had not been achieved.Wheat, corn and soybean prices all rose on the news. Wheat futures jumped 3% on Monday, hitting a high of 689.25 cents per bushel, its highest level since June 28 when the contract traded as high as 706.25 cents.Wheat prices remain well below the peak levels of 1177.5 cents per bushel reached in May last year, however.Corn futures soared to a high of 526.5 cents per bushel, while soybean futures surged to a high of 1,388.75 cents per bushel.Bulk carriers are docked at the grain terminal of the port of Odessa, Ukraine, on April 10, 2023.Bo Amstrup | Afp | Getty ImagesSimon J. Evenett, a specialist in global trade and an economics professor at the University of St. Gallen, said Monday that Russia’s withdrawal reflects the “coup de grace on a deal that was on its last legs.” He cited U.N. shipping data that showed shipments have been steadily falling year-to-date.”The demise of the Black Sea Deal is a blow for the nations sourcing cheaper Ukrainian wheat. So long as this doesn’t trigger lots of export bans, the deal’s demise is [a] minor disturbance,” Evenett said via email.”Going forward what matters is whether Russia weaponizes its wheat exports,” he added. “During the last and current harvest cycle Russia was the world’s largest supplier, exporting around 45 million metric tons.”Evenett said market participants should closely monitor the prospect of Moscow imposing an export tax increase given that this would likely raise grain prices further and help the Kremlin to finance its military campaign in Ukraine.’Indispensable role’ in global food securitySince being signed in July last year, the U.N. says the Black Sea Grain Initiative has allowed over 32 million metric tons of food commodities to be exported from three Ukrainian Black Sea ports — Odesa, Chornomorsk and Pivdennyi, previously known as Yuzhny — to 45 countries worldwide.It is for this reason that U.N. Secretary-General Antonio Guterres had described the deal as playing an “indispensable role” in global food security.Guterres said in early July that the agreement “must continue” at a time when conflict, the climate crisis, energy prices and other factors roil the production and affordability of food, while 258 million people face hunger in 58 countries worldwide.Russian President Vladimir Putin meets with servicemen at the Kremlin in Moscow on June 27, 2023. Mikhail Tereshchenko | AFP | Getty ImagesCarlos Mera, head of agricultural commodities markets at Dutch cooperative Rabobank, said Monday that while investors had been bracing for a cancellation, Russia’s withdrawal was “a blow” to markets.Mera said the initiative had supported price stability and prevented shortages across the developing world.”Ukraine will now be forced to export most of its grains and oilseeds through its land borders and Danube ports. This will significantly drive up transportation costs and pile further pressure on Ukrainian farmers’ profits,” he added.”The knock-on effect of this is it could prompt them to plant less next season, placing further pressure on supplies going forward.”Ultimately, Mera said the development means low-income countries in Africa and the Middle East will likely become more dependent on Russian wheat — a country that represents more than 20% of global wheat exports.— CNBC’s Ruxandra Iordache contributed to this report.