President Dmitry Medvedev ordered law enforcement agencies on Thursday to prevent speculators driving up food prices after the worst harvest in years and pledged help to ensure affordable food staples, Reuters reported. Russia's summer drought will lead to a "price shock" for three to six months though inflation should be 7.0 percent for the year, central bank first deputy chairman, Alexei Ulyukayev, told a banking conference. Medvedev, speaking to a state council of senior government and regional officials, complained that speculators were driving up prices for certain foods such as buckwheat -- a Russian staple for centuries. "The speculators need to be caught," Medvedev said at the meeting in Saratov, a city on the Volga river in an agricultural region hit by the drought. "There are no objective reasons for the current changes in price" for food products. "The situation should be kept under control by the government and regional leaders... If the situation changes I will take the decision to ensure our citizens have quality and affordable food... This is a priority for the state." Russia's grain harvest is expected to fall to 60-65 million tonnes this year after what the state weather agency says is Russia's worst drought in over a century from 97 million tonnes harvested in 2009. Medvedev said Russia, which was the world's third largest wheat exporter before this year's poor harvest, would seek to regain its position on world markets. "In recent years we returned Russia the status of a leading world exporter of grain and we shall move forward," he said. "Despite the unusual heat, despite the drought, our country has enough reserves of grain."