Moody's Investors Service has downgraded China's credit rating today for the first time in almost 30 years.

It expects the country's growth to slow, while its debt rises in the coming years.

China's long-term local and foreign currency issuer scores have slipped from A1 to Aa3 - down one level. This is its first downgrade since 1989 and it comes after years of stimulus programmes.

"The downgrade reflects Moody's expectation that China's financial strength will erode somewhat over the coming years, with economy-wide debt continuing to rise as potential growth slows," the agency said in a statement.

Chinese officials have said that Moody's analysis is based on the use of an "inappropriate methodology."

"Moody’s views that China’s non-financial debt will rise rapidly and the government would continue to maintain growth via stimulus measures are exaggerating difficulties facing the Chinese economy, and underestimating the Chinese government’s ability to deepen supply-side structural reform and appropriately expand aggregate demand," its Finance Ministry commented.

The country is trying to contain financial risks and to avoid asset bubbles forming while maintaining growth.

"While ongoing progress on reforms is likely to transform the economy and financial system over time, it is not likely to prevent a further material rise in economy-wide debt, and the consequent increase in contingent liabilities for the government," Moody's continued.