Moscow says that any extension or expansion of a deal allowing Ukrainian grain exports via the Black Sea would depend on the West easing sanctions.
Russia says the impact of sanctions on logistics, payments, shipping and insurance prevents it from exporting fertilisers and chemicals like ammonia and that easing those restrictions was a key part of the deal, brokered in July by Turkey and the United Nations.
United Nations officials met on Sunday (October 16) and Monday with Russia's Deputy Foreign Minister Sergei Vershinin on the issue.
The deal, which is up for renewal next month, did allow for fertilizer exports from Russia but Moscow has complained that these are still obstructed.
The UN says progress on the renewal of the deal is vital to tackle the global food crisis which has been aggravated by Russia's war on Ukraine.