The USDA said the highly contagious fungus was found in Tyrrell County, but it did not specify what type of plant the rust was found on. Since it was first discovered in North Carolina last week, a total of eight counties have seen the disease.
The spread of soya rust has picked up durin g the past week, with 25 new US counties reporting new cases of rust. But, with the harvest nearly complete, the fungus should not affect yields.
Rust, which can cut crop output by 80 percent, also has been found this year in Alabama, Georgia, Mississippi, Louisiana, South Carolina and Florida - all states that grow a relatively small amount of soyabeans.
Soya rust was first found in the continental United States last November, after spores were blown into the US Gulf Coast by a hurricane. The fungus thrives in warm, humid weather under cloudy skies, and is spread by the wind.