The National Institute for health and Clinical Excellence (NICE) has unveiled new guidelines to help people stop smoking.
The regulator said health authorities should be looking to treat at least 5% of their populations who smoke each year, and target a success rate of at least 35% after four weeks.
The guidance also says NHS Stop Smoking services should focus on ethnic minority and disadvantaged communities, while children aged between 12 and 17 should be offered advice and support on how to kick the habit.
Sir Alexander Macara, president of the National Heart Forum who chaired the NICE panel which produced the guidance, said: "Although smoking prevalence has dropped sharply since the 1970s, the decline has been much slower in the last decade.
"Those people who are still smoking are at the greatest risk of harm to their own health and the people around them.
"Although NHS Stop Smoking services have helped large numbers of people to quit smoking, smoking cessation rates are still lower among vulnerable groups, particularly pregnant women, people in routine and manual groups, and those aged 20 or under.
"We have specifically targeted these groups as they often need additional support to help them give up smoking."