The head of the World Trade Organisation has urged countries not to block or restrict exports of basic foodstuffs after Russia's invasion of Ukraine worsened tensions on global food markets.
The comments followed India's decision the same day to cap sugar exports at 10 million tonnes in the year to September, following up on a ban on wheat sales abroad.
New Delhi said the decision aimed to "maintain the domestic availability and price stability during the sugar season".
Moscow's invasion has disrupted supplies of fertiliser, wheat and other commodities from both Russia and Ukraine.
Speaking at the World Economic Forum in Switzerland, WTO chief Ngozi Okonjo-Iweala said: "We're trying to tell members also on the export prohibition, restriction side, let's keep it down."
"We don't want this to exacerbate and lead to price spikes."
In response, "we have about 22 countries now with 41 export restrictions or prohibitions on food," Ms Okonjo-Iweala said.
As well as foodstuffs themselves, "let's not forget inputs, seeds and fertiliser," she added.
She highlighted that the WTO hoped its public monitoring of such controls would deter member countries.
"Transparency helps," Ms Okonjo-Iweala said. "It helps to put pressure on members or countries that are doing this.
"For security reasons you can do this for periods of time but it has to be temporary, transparent and proportionate, so they know it cannot go on for ever."
She also said that United Nations Secretary-General Antonio Guterres "is involved" in talks to open corridors through the Black Sea for Ukrainian food exports to reach world markets.
"I know that some work is going on behind (the scenes) to try and see if we can get a solution on that," the WTO chief added.
"There's going to be huge pressure to make (corridors) happen," McKinsey analyst Clarisse Magnin-Mallez told AFP.
There is "no option apart from transporting by sea" because of the "massive volumes" that must be shifted, she added.
Ukrainian Foreign Minister Dmytro Kuleba had earlier said that a Russian proposal to lift the sanctions against Moscow so as to avoid a global food crisis was "blackmail".
Russia eyes conditional corridor for Ukraine food ships
Russia is ready to provide a humanitarian corridor for vessels carrying food to leave Ukraine, in return for the lifting of some sanctions, the Interfax news agency cited Russian Deputy Foreign Minister Andrei Rudenko as saying.
Ukraine's Black Sea ports have been blocked since Russia sent thousands of troops into Ukraine on 24 February and more than 20 million tonnes of grain are stuck in silos in the country.
Russia and Ukraine usually account for nearly a third of global wheat supplies and the lack of significant grain exports from Ukrainian ports is contributing to a growing global food crisis.
Ukraine is also a major exporter of corn and sunflower oil.
Western powers have been discussing the idea of setting up "safe corridors" for grain exports from Ukraine's ports, although these would need Russian consent.
"We have repeatedly stated on this point that a solution to the food problem requires a comprehensive approach, including the lifting of sanctions that have been imposed on Russian exports and financial transactions," Mr Rudenko was quoted assaying.
"And it also requires the demining by the Ukrainian side of all ports where ships are anchored. Russia is ready to provide the necessary humanitarian passage, which it does every day."
The RIA news agency quoted Mr Rudenko as saying Russia was in touch with the United Nations on the issue.
Ukrainian Foreign Minister Dmytro Kuleba poured scorn on the suggestion that Moscow wanted to allow Ukraine to ship grain.
"You could not find a better example of a blackmail in international relations," he told the World Economic Forum in Davos. "If anyone is buying it, I think there is a problem with that person, and we shouldn't waste too much time trying to understand why that person is making that point."
Odessa is Ukraine's main deep-water port and used to handle almost all its grain exports.
It has suffered a number of Russian missile attacks, and Kyiv fears that Moscow wants to capture it as it has other Ukrainian ports, potentially through an amphibious assault.
Mr Rudenko was also quoted by Interfax as saying that any escort by Western ships of Ukrainian vessels carrying grain would "seriously exacerbate the situation in the Black Sea".
Britain said yesterday it had no plans to send its warships to help get food exports out of Odessa.
Euronext wheat fell to a two-week low in Paris after Russia said it would allow Ukrainian food exports to resume by sea under certain conditions.
Russia's defence ministry said the port of Mariupol, the Ukrainian city on the shallow-water Azov Sea which was taken by Russia after a long siege, was operating normally after Russian forces finished removing mines from there.
