A sign and logo showing the Moody's rating agency is displayed at the company headquarters in New York, Sept. 18, 2012. AFP-Yonhap

Global credit appraiser Moody's Investors Service said Thursday it has affirmed its credit rating on South Korea at "Aa2," with a stable outlook.

Moody's has maintained the country's sovereign credit rating at "Aa2," the third-highest level on the company's table, since December 2015, when the agency upgraded it from "Aa3."

"The affirmation of the rating is supported by (South) Korea's very high degree of economic diversity and competitiveness, its still-strong fiscal buffers, and vigilant institutional management around key challenges," the agency said in a report.

The stable rating outlook reflects "limited risks" to the country's credit profile, as its credit fundamentals will remain exposed to material and long-lasting impediments to global trade, the agency said. It also noted that longer-term credit constraints for the sovereign are centered mostly on the government's ability to implement structural reform in the face of rapid population aging. (Yonhap)