Hong Kong (CNN Business) China is warning speculators betting against its currency to prepare for a fight.

The yuan on Friday slid close to its lowest point since the global financial crisis in 2008. But it recouped its losses after combative comments from a Chinese central bank official.

"For those who are trying to short the renminbi, we fought hand to hand a few years ago so we are very familiar with each other," Pan Gongsheng, deputy governor of the People's Bank of China, said at a news conference in Beijing. "I think it's still fresh in our memory."

He reiterated the bank's position that it wants to keep the yuan broadly stable.

The currency has now slumped more than 9% against the dollar since January, coming under pressure from the US Federal Reserve's moves to hike interest rates and fears about China's slowing economy. The decline has added to the tensions between Beijing and the Trump administration, which are locked in an escalating trade war.