By Li Hongmei

The US Federal Reserve on Tuesday began supplying banks with new US$100 bills outfitted with greater security measures to deter counterfeiters, but still with Founding Father Benjamin Franklin's face on the front.

"The new design incorporates security features that make it easier to authenticate, but harder to replicate," Federal Reserve Board Governor Jerome H. Powell said in a statement Tuesday.

The new note includes two new security features, the Federal Reserve said: a blue 3-D security ribbon with images of bells and the number 100; and a color-changing bell in an inkwell. Around 3.5 billion of the new $100 bills have been stockpiled, Reuters reports, citing Sonja Danburg, a program manager for US currency education at the Federal Reserve.

Currently there are around $900 billion in US$100 notes in circulation, of which one-half to two-thirds are outside the United States, Danburg said. The US central bank said Tuesday that it is not necessary for consumers to trade in older US$100 notes for the new ones.

Under US government policy, all designs of US currency are legal tender irrespective of when they were issued, the Federal Reserve said.