A UN-brokered deal to allow Ukrainian grain and fertiliser exports to resume is set to be signed in Istanbul, Turkish officials said on Thursday, although the UN cautioned that nothing was set in stone.
Turkish President Recep Tayyip Erdogan, UN Secretary General Antonio Guterres and officials from Russia and Ukraine would oversee the signing ceremony on Friday, Mr Erdogan's spokesman Ibrahim Kalin said on Twitter.
UN spokesman Farhan Haq said Mr Guterres would travel to Istanbul on Thursday, but would not confirm when the signing might take place.
"The situation remains a little bit fluid, so I can't really say when something will be signed," Mr Haq said. "We're not quite there yet."
A deal between Ukraine and Russia, which have been at war since Moscow's invasion on February 24, would relieve a global food crisis caused by blocked Black Sea grain exports.
Up to 25 million tonnes of wheat and other grain have been blocked in Ukrainian ports by Russian warships and landmines Kyiv has laid to avert an amphibious assault.
US State Department spokesman Ned Price welcomed the prospective deal and credited Ankara — which has good relations with Kyiv and Moscow — for its role in negotiating it.
But Mr Price said: "We should never have been in this position in the first place. This was a deliberate decision on the part of the Russian Federation to weaponise food."
News of Friday's signing was a "welcome development", he said, "but what will really matter is the implementation of this agreement.
"We, of course, will continue to work with our partners to hold Russia accountable for its implementation."
The first direct talks between the warring sides' military delegations since March, attended in Istanbul last week by Turkish and UN officials, came up with an initial draft for resolving the impasse.
The sides were meant to have met again this week for the possible signature of a formal agreement.
But Russian President Vladimir Putin threatened to derail the talks by warning on Tuesday that he expected any agreement to also address his own country's blocked grain exports.
The five-month war is being fought across one of Europe's most fertile regions by two of the world's biggest producers of grain.
Almost all of the grain is usually shipped out of the region across the Black Sea.
Turkish Foreign Minister Mevlut Cavusoglu on Thursday acknowledged Mr Putin's concerns.
"When we resolve this issue, not only will the export path for grain and sunflower oil from Ukraine be opened, but also for products from Russia," Mr Cavusoglu said.
"Even if these Russian products are not affected by sanctions, there are blockages concerning maritime transport, insurance and the banking system," he added.
"The United States and the EU have given promises to lift these."
Agencies contributed to this report