China should stop hoarding food and fertiliser to ease a global supply crisis caused by the Iran war, a former World Bank president has told the BBC.

David Malpass, who also served as Treasury Under Secretary for International Affairs under US President Donald Trump from 2017 to 2019, was speaking to the World Service's World Business Report on the eve of the Trump-Xi summit in Beijing.

"They have the biggest world stockpile of foodstuffs and of fertiliser," he said. "They can stop building their stockpiles."

His comments come as nations around the world scramble to secure fertiliser supplies ahead of spring planting, with the closure of the Strait of Hormuz severely disrupting shipments.

Earlier this month, the boss of one of the world's biggest fertiliser producers warned that the interruption to supplies could cost up to 10 billion meals a week globally and would hit poorest countries hardest.

Svein Tore Holsether, chief executive of Yara, told the BBC that reduced crop yields as a result of lower fertiliser use could lead to a bidding war for food.

China has halted exports of several types of fertiliser since March, citing the need to protect domestic supplies.

This came on top of restrictions that have been steadily put in place since 2021.

Last year, China accounted for about 25% of global output of fertiliser, with exports totalling more than $13bn (£9.6bn).

Malpass, who ran the World Bank from 2019 to 2023, also said that Beijing's claim to be a developing nation was no longer credible.

"They present themselves as a developing country when they're the second biggest economy in the world and in many ways rich," he said.

"And yet they still have the pretence of being a developing country in the WTO and in the World Bank, and they could suspend that," Malpass added.

Liu Pengyu, spokesperson for the Chinese embassy in Washington DC, told the BBC in an emailed statement: "China is committed to maintaining the stability of global food and fertilizer markets.

"The root causes behind the current disruptions in global food and fertilizer supply chains are crystal clear; this blame cannot be shifted onto China," he added.

In response to Malpass's comment on China's status as a developing country, Liu said: "China is universally recognized as the largest developing country - a designation grounded in ample factual evidence.

"Upholding its status as a developing country is a legitimate right of China."