The Asian central bank is burning through its massive forex reserves to halt a rapid slide in the value of the renminbi as the Chinese economy slows.

China’s foreign exchange reserves have declined to their lowest level since 2012, highlighting how the Asian country's central bank has sold dollars in a bid to prevent a rapid depreciation in the renminbi, according to the South China Morning Post.

Reserves shrank by $99.5 billion in January to $3.23 trillion, according to a People’s Bank of China statement issued at the weekend when the markets were closed. The stockpile fell by more than $500 billion last year.

The reserves are being used because policymakers are trying to stem a rapid deceleration of the renminbi as the Chinese economy slows down.