The U.S. fast-food chain Burger King will stop its tradition of giving away free toys in its kids' meals in the UK branches in a bid to tackle the growing problem of plastic waste. /VCG Photo

The move was a response to a campaign led by two young sisters in the country who launched a petition against plastic toys, which was signed by more than half a million people. /VCG Photo

Fer Machado, the company's global chief marketing officer, announced the decision on Wednesday and said it would save 320 tons of plastic a year. /VCG Photo

The company also encourages customers to return old plastic toys, which are planned to be melted to reuse. /VCG Photo

Burger King's rival McDonald's was also named in the petition. However, it said it won't stop giving away Happy Meal toys but will provide customers with the option to swap the free toy for a fruit bag. /VCG Photo