The last ship to sail under a deal allowing Ukraine to export its grain has left the country's Black Sea port of Odesa, a day before an extension deadline, MarineTraffic data site says.
It says the TQ Samsun left on Sunday - a claim backed by Reuters news agency.
Russia has not agreed to extend the UN-brokered deal unless its demands on its own grain and fertilisers are met.
The 2022 deal was struck amid fears of global food shortages after Russia's full-scale invasion of Ukraine.
Both Ukraine and Russia are among the world's top grain exporters.
MarineTraffic says the Turkish-flagged ship left Odesa just after 08:00 local time (05:00 GMT) and was heading south to the Turkish city of Istanbul.
Ukraine has so far not publicly commented on the issue.
On Saturday, Russian President Vladimir Putin said commitments to remove obstacles to Moscow's own food exports and other key provisions had not been met, signalling that Moscow could suspend its participation in the agreement.
"The main goal of the deal, namely the supply of grain to countries in need, including on the African continent, has not been implemented," the Kremlin leader said in a phone call to South African President Cyril Ramaphosa.
Moscow also wants its Rosselkhozbank - a bank that handles agricultural payments - to be reconnected to the global Swift payment network.
Earlier this year, the European Union said it was not considering reinstating Russian banks sanctioned because of Moscow's invasion of Ukraine.
On Friday, Turkish President Recep Tayyip Erdogan said he was confident the deal would be extended again, after speaking to Mr Putin.
The deal is meant to be extended for 120 days at a time, but in March and May 2023 Russia agreed to extensions of only 60 days.
Several days before the last extension, Ukrainian President Volodymyr Zelensky held urgent talks with UN Secretary General António Guterres.
"We are interested in ensuring that there is no hunger in the world," Mr Zelensky said.
Ukrainian exports by sea from the country's Black Sea ports were initially blocked by Russian warships following the invasion in February 2022.
More than 30m tonnes of grain and other foods have left Ukraine under the deal providing a safe corridor across the Black Sea.
The UN says that:
- 47% of Ukraine's grain has gone to "high-income countries" including Spain and Italy
- 26% to "upper-middle income countries" such as Turkey and China
- 27% to "low and lower-middle income countries" such as Egypt and Sudan
Mr Putin has criticised Ukraine for not exporting more to developing countries.
But the UN says the grain deal has benefited people throughout the world because it has brought more food products onto the global market and therefore reduced global prices.