Production of what is described as the world's most secure coin, the British pound, has started, Chancellor George Osborne announced Thursday.

The new twelve-sided, one-pound coins have started to roll off the production line at a rate of over 4,000 a minute at the Royal Mint in South Wales. They are to enter circulation in March 2017, Osborne said.

The coin was designed by 15-year-old schoolboy David Pearce and features the English rose, the Scottish thistle, the Welsh leek, and the Irish shamrock, emblems of the four parts of the UK. His winning design was chosen out of 6,000 entries in a public competition organised by The Royal Mint.