Fitch Ratings on July 13 affirmed China's long-term foreign- and local-currency issuer default ratings at A+, with a stable outlook, citing the strength of the country's external finances and macroeconomic track record.
China's short-term foreign- and local-currency issuer default ratings were also affirmed, at F1+.
The rating agency said China's near-term growth prospects remain favorable, and the country has addressed domestic and external pressures over the past year through economic policies.
However, Fitch warned that a further increase in leverage as part of a push to meet ambitious GDP growth targets raises the possibility of economic and financial shocks and will limit growth prospects over the medium term.
China's GDP growth will slow down to 5.9% in 2018 from 6.5% in 2017 due to tighter monetary conditions.
Fitch said the most significant risk factor for the sovereign rating remains rising debt levels across the nonfinancial sector, combined with the low credit quality of Fitch-rated banks in its financial system.
Official aggregate financing excluding equity is projected to rise to 208% of GDP in 2017 from 201% in 2016 and 114% in 2008, Fitch said. A broader credit measure incorporating activity not directly captured in the official series will increase to around 270% at the end of 2017.
Fitch said Chinese household debt remains moderate despite its rapid growth in recent years, but the country's corporate sector has become the most highly indebted among major economies globally, according to data from the Bank for International Settlements.
In May, Moody's downgraded China's long-term local- and foreign-currency issuer ratings to A1 from Aa3 and revised the outlook to stable from negative.