China's debt rating was upgraded by Moody's Investors Service, citing the country's swelling foreign-currency reserves, surging exports and improvements to the banking system.

The country's long-term foreign-currency rating jumped to A1, the fifth-highest ranking, from A2, the ratings company said in a statement today.

"Official foreign exchange reserves continue to grow and now exceed $1.3 trillion, and external obligations of the government and State-owned banks are a small fraction of that sum," said Moody's Senior Vice President Tom Byrne. The performance of the export sector was "formidable."

China's trade surplus climbed 84 percent from a year earlier in the first half to $112.5 billion.

The nation has improved the strength and supervision of State-owned commercial banks, Moody's said today.

Hong Kong's debt rating was raised to Aa2 from Aa3 after government finances improved, the ratings company said in a separate statement.

"The Hong Kong government has almost no debt and large and growing fiscal reserves, equivalent to about one quarter of GDP," said Moody's Vice President Steven Hess in a statement.