A ban on exports of wheat and other grain is now in force in Russia, due to a heatwave and wildfires.
Russia was the world's third largest wheat exporter, behind the United States and Canada last year.
Egypt is its largest export market, followed by Turkey, Syria, Iran and Libya.
President Dmitry Medvedev said last week the events had destroyed a quarter of the crops.
The ban extends from 15 August - 31 December. The BBC reports it could be extended into next year.
On Thursday, the US Department of Agriculture lowered its outlook for world wheat production after revising its crop forecast for Russia.
The agency said global production would be 15.3m tonnes lower at 645.7 million tonnes.
The outlook for Russia was lowered by 15% to 45 million tonnes.