China’s Central Bank cut the guiding rate for their national currency for the second day in a row, impacting world markets as the Chinese government attempts to boost exports.

Officials with the Central Bank tried to dampen the shockwaves being sent through world markets by saying the day’s move was not part of a sustained devaluation of the Chinese currency.

“Looking at the international and domestic economic situation, currently there is no basis for a sustained depreciation trend for the yuan,” it said in a statement.

The Yuan was down 1% Wednesday after a 1.9% devaluation Tuesday.  The total overall decline is the largest in two decades and comes after Chinese government reports showed exports from the nation fell 8% during July.

The currency is now going to be set based on market forces where it previously had been set solely by the People’s Bank of China alone.

“Greater exchange rate flexibility is important for China as it strives to give market-forces a decisive role in the economy and is rapidly integrating into global financial markets,” the International Monetary Fund said in a statement regarding the Chinese action.

Some U.S. officials were harsh in their comments toward China’s action.

“For years, China has rigged the rules and played games with its currency. Rather than changing their ways, the Chinese government seems to be doubling down,” New York Senator Chuck Schumer told the BBC.

The U.S. Treasury’s response was more neutral.

“We will continue to monitor how these changes are implemented and continue to press China on the pace of its reforms, including additional measures to transition to a market-oriented exchange rate and its stated desire to move towards an economy that is more dependent on domestic demand, which is in China and America’s best interests. Any reversal in reforms would be a troubling development.”

As of noon EST, the Dow Jones Industrial Average was down 160 points and all major markets around the world were lower.