Philippine President Rodrigo Duterte has imposed a ban on smoking in public places - with offenders facing up to four months in jail.

The hardline leader signed an executive order for an 'absolute ban' on smoking in schools, gas stations, hospitals, 'food preparation areas' and stairwells.

Anyone who breaks the rules could face $100 fines or a spell of four months behind bars.

Duterte has already launched a bloody war on drugs in the country in which thousands have died.

Philippine President Rodrigo Duterte (pictured) has imposed a ban on smoking in public places - with offenders facing up to four months in jail

A third of the population - around 17 million people - still smoke meaning the new law could prove hard to enforce.

But the ban received broad support on Friday, with anti-tobacco activists hailing it as a victory and some smokers saying they were now prepared to kick the habit.

Even an industry lobby group, the Philippine Tobacco Institute (PTI), said it supported the regulation and acknowledged the health objectives.

The executive order to ban smoking was delayed from last year due to corporate resistance. It sets strict guidelines on designated smoking areas.

Shares in LT Group Inc, the Philippines' top cigarette maker, fell as much as 4.4 percent to near one-month low following the news.

The law takes effect 60 days after its publication in a newspaper.

'This is a victory for us,' said Maricar Limpin, executive director of Action on Smoking and Health Philippines. 'This (order) highlights the need to protect the people from the harsh exposure to second hand smoke.'

Health Secretary Paulyn Jean Rosell-Ubial expressed optimism the ban would encourage people to quit.

More than a million Filipinos quit smoking between 2010 and 2015, the biggest ever reduction in the world, she said.

'By 2020, when we do the next survey, we expect almost or even higher reduction in cigarette prevalence,' she told CNN Philippines.

Duterte has already launched a bloody war on drugs in the country in which thousands have died

Jojo Primivida, a 48-year-old courier driver and father of six, said he was ready to quit, aware of the tough regulations and penalties.

'I know I can do it. I'm a heavy smoker before, but now I smoke only after meals,' he said, puffing a Marlboro at a public area near his workplace.

Office worker Jobell Lisana said he has been smoking since school days but was willing to stop.

'Quitting is easier said than done, but I will probably stop because now there will be fines and penalties.'

The PTI lobby group said it agreed with the new rules.

'We have always supported regulation of public smoking as provided for under the national law including the designation of areas where smoking is allowed,' it said.

The group represents tobacco companies such as Philip Morris Philippines Manufacturing Inc, Fortune Tobacco Corp, British American Tobacco, JT International (Philippines) Inc, among others.