The head of the Russian Grain Union said on Monday the Black Sea grain deal to facilitate Ukrainian agricultural exports had not yielded anything positive for Russia or helped facilitate supplies to the global market, reported Reuters. 

Russia has repeatedly criticized the initiative - brokered last July by Turkey and the United Nations - and said it would not be extended beyond May 18 unless a list of demands are met.

Moscow wants the West to remove obstacles to the export of Russian grain and fertiliser, including the reconnection of Russian Agricultural Bank (Rosselkhozbank) to the SWIFT payment system.

Other demands include the resumption of supplies of agricultural machinery and parts, lifting restrictions on insurance and reinsurance, the resumption of the Togliatti-Odesa ammonia pipeline and the unblocking of assets and the accounts of Russian companies involved in food and fertiliser exports.

The agreement created a protected transit corridor to enable exports to resume from three ports in Ukraine, a major producer of grains and oilseeds.

Under the pact, Ukraine has been able to export some 28.8 million tonnes of agricultural products, including 14.6 million tonnes of corn and 7.8 million tonnes of wheat, according to UN data.

UN Secretary-General Antonio Guterres on Monday urged the continued implementation of the deal and a related pact in which the United Nations pledged to help facilitate Russia's own grain and fertilizer exports.

"They clearly demonstrate that such cooperation is essential to creating greater security and prosperity for all," he said at a meeting chaired by Russia's Foreign Minister Sergei Lavrov.