Fitch Ratings on May 30 affirmed Banco Nacional de Costa Rica's long- and short-term national ratings at AA+(cri) and F1+(cri), respectively. The outlook of the long-term rating is stable.

In affirming the state-owned bank, Fitch said the ratings reflect the Costa Rican government's capacity and propensity to support the bank. The ratings are in line with Fitch's sovereign BB rating for Costa Rica.

The rating agency said the bank's asset quality metrics were "adequate and consistent" with its risk appetite, market dominance and state-owned nature.

Fitch noted the lender's nonperforming loan levels over 90 days have remained below 2.4% since 2014. This level is slightly higher compared to the country's banking system, but "reasonable" for the bank's size as a state-run bank.

"The diversification of the loan portfolio is moderate and the exposure to foreign exchange risk is close to the system average; However, further deterioration on the Costa Rican currency could pressure the quality of the bank's assets," Fitch noted.

Fitch said Banco Nacional maintains a "good" capital base considering its capacity to generate internal capital, though it tends to be lower than the growth rate of its loan portfolio.