China vowed on Tuesday that it would make “liveable” cities a central goal of China’s urban planning, amid persistent problems over choking smog that frequently blankets the populous east and north.

Under a plan released after what leaders dubbed the Central Urban Work Conference and overseen by President Xi Jinping, urban development should be focused on “creating environments where people can live in harmony with each other and nature”.

“The government will take a more sophisticated approach to its urban planning and encourage enterprises and citizens to participate in creating the cities of the future,” according to a statement released by the official Xinhua news agency.

Nature and tradition should be respected in city planning and a low-carbon concept prioritized, the report added.

“Urban construction should take nature as beauty,” it said.

Green belts and bodies of water should be established around cities and sprawl controlled, Xinhua added.

China has vowed repeatedly over the years to tackle pollution and yet none of its plans have has had a lasting effect.

Capital city Beijing has already issued two “red alerts” for smog this winter, which see cars taken off roads and schools and factories closed.

A red alert is triggered when the government believes air quality will surpass a level of 200 on an index that measures various pollutants for at least three days. The U.S. government deems a level of more than 200 to be “very unhealthy”.

Since the end of last week, a swathe of northern China has been hit by severe air pollution, including the province of Hebei which surrounds Beijing and the nearby conurbation of Tianjin.