Turkey, the UN and others looked for ways to salvage the Ukrainian grain export initiative after Moscow said it would pull out indefinitely following an attack on its Black Sea naval fleet.

A Russian official didn’t definitely rule out a return, adding to uncertainty around the pact, which has seen more than 9 million tons of grains and other foodstuffs shipped since August. 

Russia said Saturday it was suspending the agreement after its ships off Sevastopol in annexed Crimea were hit by aerial and underwater drones it blamed on Ukraine. The extent of damage to the vessels remains unclear. 

Turkey and the United Nations, which toiled together for months to broker the safe-transit deal for grain shipments from three Ukrainian ports, went back to work on Sunday. 

Turkey, in a statement posted on Twitter, said Defense Minister Hulusi Akar was speaking with counterparts, reminding them that the export initiative is “for the good of the entire humanity and that crises can be solved through goodwill and dialogue.”  

UN Secretary General Antonio Guterres said he would postpone his departure for the Arab League summit in Algeria by a day to focus on the grain initiative. Among others, he conferred Sunday with EU foreign policy chief Josep Borrell. 

Russian Foreign Minister Andrei Rudenko didn’t explicitly rule out a return to the grain deal when questioned by journalists in Moscow on Sunday, and said Russia expected to be in contact with the UN and Turkey soon.  

But the next steps could only be determined after a full investigation into Saturday’s drone attack, Rudenko said. It wasn’t clear from his comments who should conduct such a probe. 

Russia’s defense ministry concluded earlier that Ukraine had launched the attack from the Odesa region, epicenter of the grain export initiative, and potentially used at least one civilian grain vessel -- claims Kyiv denied.  

Senior Russian officials have spent weeks criticizing the export deal ahead of a Nov. 19 renewal deadline. Ukraine in turn has accused Moscow of delaying progress through the safe-passage corridor between Odesa and Turkey to create a growing backlog of ships.  

Russia Suspends Ukraine Grain Export Deal; Biden Slams Move

If the corridor remains closed, it could again send shocks through global crop markets, exacerbating hunger, especially in the world’s poorest countries, and adding to food inflation. 

Ukraine is one of the world’s biggest wheat, corn and vegetable oil providers, and the bulk of its exports go by sea. Even before Russia’s latest move, many food importing nations have been struggling to pay for purchases because of the soaring dollar and strained budgets.

“The initiative provided needed grains and oilseeds to a hungry world,” said Joseph Glauber, a former chief economist at the US Department of Agriculture who now serves as a senior fellow at the International Food Policy Research Institute in Washington. 

The grain corridor has had an key impact on world supplies since opening three months ago -- Ukraine has shipped about 9.3 million tons of goods, and prices for corn and wheat have retreated from the highs seen earlier in the year. But exporters and officials have warned for weeks about the rising -- and costly -- backlog of ships waiting for inspection to proceed. 

Millions of tons of crops are waiting at sea and ports. Over 200 vessels that are part of initiative are now essentially frozen in place, Ukraine’s infrastructure ministry said on Facebook.

Under the terms of the deal, all vessels need to be inspected before entering or leaving Ukrainian ports.

Read: One Missile Shook Ukraine’s Grain Trade. Another Might Kill It

Outbound vessels that have already reached Istanbul are being inspected Sunday and Monday, but no new grain ships will sail from Ukraine for now, Turkey’s defense department said.

Earlier, Ukraine said a 40,000-ton cargo of wheat purchased under the UN’s World Food Programme and bound for Ethiopia had been loaded but couldn’t leave port on Sunday. 

Russia’s announcement that it will withdraw from the deal drew widespread criticism. US President Joe Biden said it will increase starvation, describing the move as “outrageous.”

Mykhailo Podolyak, an adviser to President Volodymyr Zelenskiy’s chief of staff, called Russia’s claims of drones launched from Odesa “invented.” The grain exporting hub is more than 300 kilometers (186 miles) from Sevastopol. 

“Since the deal took effect, Russia hinted many times that it was ready to disrupt it,” he told Bloomberg News. “It is the usual Russian tactic -- to break its promises, to violate agreements, to blackmail and threaten.” Moscow is looking for leverage ahead of the G-20 meeting in Indonesia in mid-November, Podolyak added.  

The grain-corridor deal faced hurdles and skepticism from the start, as insurers and vessel owners weighed the risks of sending cargoes through the Black Sea as the war raged on. Russian strikes on the port of Odesa a day after the deal was signed served as a stark reminder of the risks.

And there is still lots left to ship. Ukrainian silos were already overflowing with last year’s crops when the corridor opened and farmers are now reaping a new harvest, while planting wheat and barley that will be collected next year. And with hundreds of grain trucks lining the road toward the Odesa ports, the effort took on a growing urgency as the November deadline to renew the deal drew closer. 

Russian President Vladimir Putin has repeatedly complained about the deal, saying not enough shipments were being sent to poor nations. Russia has also said its own grain and agricultural goods were not being allowed the same access to global markets, although the US Department of Agriculture still estimates it will be the world’s top wheat exporter this season.

However, claims that developing nations aren’t benefiting from the safe-corridor deal aren’t backed up by data, which show a considerable segment of the shipments have gone to these countries.