China's Finance Ministry has voiced its disapproval with Standard & Poor's downgrade of its credit outlook, saying rating agencies have overestimated the difficulties the economy faces and underestimated the ability of the government to handle them.

"Rating agencies have overestimated the difficulties the economy faces and underestimated the ability of the government to press ahead and reform and handle risk," said Shi Yaobin, vice minister of finance in a formal statement on Friday afternoon.

"Their worry over the restructuring of the economy, the debt problem with the real economy, the SOE reform, financial risk, is unnecessary," he said.

Standard & Poor's Ratings Services cut the outlook on China's government credit ratings to "negative" from "stable" on Thursday, becoming the second major global credit rating agency to do so after Moody's Investors Service.

S&P cited the adjustment to its expectation that China will show modest progress in economic rebalancing and credit growth deceleration. It said government and corporate leverage ratios are likely to deteriorate, and the investment rate could be well above the sustainable levels of 30-35 percent of GDP and among the highest ratios of rated sovereigns.

That said, S&P maintained its 'AA-/A-1+' sovereign credit ratings for China, and acknowledged some encouraging signs in the economy, including the anti-corruption campaign, reforms of budgetary frameworks and the financial sector, government's growing tolerance toward companies' closure or default. But it cautioned that the pace and depth of SOE reform may be insufficient to attenuate the risks of credit-fueled growth.

Shi said as reform measures take effect and China achieves a medium to high growth rate, it will provide a solid foundation for a high credit rating.

This is not the first time that officials have rebuked global rating agencies' moves. Responding to concern over Moody's lowering of the outlook at the recent China Development Forum, Finance Minister Lou Jiwei said he actually doesn't "care" , as he didn't see a negative fallout from any market, international or domestic.

The Finance Ministry on Wednesday released a Q&A to respond to Moody's action. It said the action was due to "insufficient knowledge" about China's economy, and pointed major rating firms' flawed history in assessing other economies.