The Secretary General of the United Nations has warned there is a "real risk of food shortages next year".

He said a shortage of exports from Russia - which are not subject to sanctions - was behind a fall in the amount of land under cultivation in West Africa and some other parts of the world, which will lead to food shortages next year unless fertilisers are distributed rapidly.

In a stark warning, Antonio Guterres said there was a "fertiliser crunch" in the world today, mainly caused by the war in Ukraine, which was contributing to "a real risk of famines next year".

A shortage of fertilisers, such as ammonia from Russia, has led to a reduction in the amount of land under cultivation this year.

Coming on top of severe drought and the flooding of Pakistan's most productive farm land, the fertiliser shortage and reduction in output is leading to a global food shortage, which will hit the poorest nations hardest.

Mr Guterres spoke with Russian President Vladimir Putin today in an effort to broker a deal to increase the amount of Russian food and fertiliser exports through the Black Sea.

He told reporters "obstacles to the export of Russian food and fertilisers had already led to a fertiliser crunch" in the world.

The UN Secretary General is also involved in a dialogue with Russia and Ukraine over the continued safe operation of the Zaporizhzhia nuclear power plant in Ukraine.

He said that staff from the UN's International Atomic Energy Agency remained on site, and there had been no shelling around the plant for three days. He said electricity supplies needed to cool the reactors remained intact.

He declined to discuss the contents of his call with President Putin, but said the prospects of a peace deal between Russia and Ukraine "remained minimal".

The UN, he said, would continue to seek concrete solutions to issues such as nuclear safety, prisoners of war, and food and fertiliser exports.

Meanwhile, the Kremlin has said that the Russian President told Mr Guterres during the phone call that the "priority" should be to send Ukrainian grain to countries in greatest need.

During the call, "the attention was mainly focused on implementing the Istanbul agreements on exporting Ukrainian grain... Both sides emphasised the importance of meeting the needs, as a priority, of those in Africa, the Middle East and Latin America who need food," the Russian presidency said in a statement.

On the eve of the UN General Assembly next week, Mr Guterres said he will tell the world's political leaders about his recent trip to Pakistan to see the flooding there.

He said what he witnessed there was a warning that the world faced "permanent and ubiquitous damage" from climate change.

The area affected by flooding, he said, was three times the size of Portugal - his home country. He said efforts to prevent climate change have "flatlined" in the developed world.

He said he will use next week's General Assembly to urge leaders to boost emissions reduction measures and raise their climate change targets to stop global average temperatures rising by more than 1.5C - something they have failed to do so far in the COP process.

Additional reporting AFP