LONDON - A levy on the amount of sugar used in soft drinks comes into force from Friday, the British Treasury said in a statement Thursday.

Millions of children across Britain will benefit from the government's so-called "sugar tax" aimed at tackling childhood obesity, said Public Health Minister Steve Brine.

Ahead of the introduction of the tax on soft drinks, 50 percent of manufacturers have already reduced sugar content in their products, saving the equivalent of 45 million kilograms of sugar every year.

Brine said: "Our teenagers consume nearly a bathtub of sugary drinks each year on average, fuelling a worrying obesity trend in this country. The Soft Drinks Industry Levy is ground-breaking policy that will help to reduce sugar intake, whilst funding sports programs and nutritious breakfast clubs for children.

"The progress made so far on our obesity plan is promising -- but with one in three children still leaving primary school overweight or obese, we have not ruled out doing more in future."

Soft drinks manufacturers who don't reformulate will pay the levy, which is expected to raise nearly $340 million each year.

The money raised by the tax will go towards funding sports facilities in schools, and give children access to top quality physical education (PE) equipment. The levy will also give a funding boost for healthy school breakfast clubs.

Exchequer Secretary to the Treasury, the MP Robert Jenrick, visited the Lucozade Ribena Suntory factory Thursday, to see how it has led the way in reformulating its soft drinks.

Jenrick said: "The Soft Drinks Levy is one part of our plan to tackle childhood obesity. From Friday, soft drinks which contain too much added sugar will need to pay a fee. All revenues raised through the levy will directly fund new sports facilities in schools as well as healthy breakfast clubs, ensuring children lead healthier lives.

"We want to persuade manufacturers to reformulate their drinks and lower the sugar content.

"In England alone a third of children are obese or overweight when they leave primary school, and evidence shows that 80 percent of kids who are obese in their early teens will go on to be obese adults."

Companies will have to pay 24 pence ($0.34) per liter of drink if it contains 8 grams of sugar per 100 milliliters and 18 pence ($0.25) per liter of drink if it contains between 5 and 8 grams of sugar per 100 milliliters.