United Nations aid chief Martin Griffiths voiced confidence on Monday that a U.N. and Türkiye-brokered deal allowing Ukrainian Black Sea grain exports could be extended and even expanded despite apparent revenge strikes by Russia on Kyiv.

The four-month deal, agreed in July, has allowed more than 6 million tons of grains and other foods to be exported and could expire next month. Griffiths and U.N. trade official Rebeca Grynspan are set to travel to Moscow this month to discuss the deal with Russian officials.

"Our view at the U.N. is we of course should seek its renewal, and I’m reasonably confident that we will see it (renewed)," Griffiths said in a Geneva press briefing in response to a question about the impact of the latest escalation in a war that has lasted more than seven months.

"But it needs to go beyond a four-month cycle. We need to see it renewed for a year," he said.

Griffiths added that U.N. officials were working "deeply and intensely" to extend and expand it, to possibly include more fertilizer and additional capacity.

Russia complains that despite the Black Sea agreement, it is not able to sell its food and fertilizers due to the sanctions on its financial and logistics sectors.

The July deal included ammonia, a key ingredient in nitrate fertilizer. A pipeline transporting ammonia from Russia’s Volga region to Ukraine’s Black Sea port of Pivdennyi (Yuzhny) was shut down when Russia invaded Ukraine on Feb. 24 and officials are trying to broker a resumption.

"Getting ammonia out to the world is of the highest priority," he said, adding that farmers needed to know soon about availability in time for next year’s harvest.

Griffiths said the systems and procedures already in place have been working well, and "they can be used, and even I hope expanded when we go into the renewal."

The prices of synthetic fertilizers – based on nitrogen, phosphorus or potash – have tripled over the past year and a half following supply disruptions from Russia, which was the world’s largest exporter, and the soaring price of gas which is essential in the manufacturing process.

The U.N.’s food and agriculture agency said world food prices continued to fall in September for the sixth consecutive month. However, its cereal price index edged up 1.5% from August.

A meeting of fertilizer producers will be organized in Paris ahead of the G-20 summit in Indonesia in November, in order to intensify production.