ROME (Reuters) - International food and feed prices could rise by between 8% and 20% as a result of the conflict in Ukraine, triggering a jump in the number of malnourished people around the world, the U.N. food agency said on Friday.

       In a preliminary assessment on Russia's invasion of Ukraine, the Food and Agriculture Organization (FAO) said it was not clear if Ukraine would be able to harvest crops during a protracted conflict, with uncertainty also surrounding Russian food exports.

       FAO said Russia was the world's largest exporter of wheat, while Ukraine was the fifth largest. Together, they provide 19% of the world's barley supply, 14% of wheat, and 4% of maize, making up more than one-third of global cereal exports.

       (Reporting by Crispian Balmer; Editing by Gavin Jones)