ULAN BATOR, Jan. 10 -- Mongolia's National Security Council (NSC) on Tuesday approved Ulan Bator Municipality's move to prohibit migration to the capital as a measure to reduce air pollution.

Batbold Sundui, mayor of Ulan Bator (UB), said: "My decisions are for the best interest of UB residents. Because of smog, our right to live in a safe and healthy environment has been violated."

"All migration to Ulan Bator from the countryside except those people that require long-term medical treatment and those who purchased apartments shall be prohibited until Jan. 1, 2018," Batbold said.

The mayor earlier presented the prohibition to the NSC, members of which include Mongolia's president, speaker of the parliament and prime minister.

The council approved it, while saying the prohibition can be extended if needed.

Under the ban, the sale of stoves, except those using biofuel and gas, will be banned, new settlement areas for rural migrants will be established far from the capital city, and city expansion will be restricted.

The Municipal Office pledged to gradually replace stoves that burn raw coal.

About 300,000 households in Ulan Bator's slum districts burn raw coal, plastics and rubber tires for heating and cooking in their homes. The smoke generated by these households is the primary cause of the air pollution in Ulan Bator, researchers said.

"We are forced to make these decisions as the current air pollution violates our right to live safely and healthily," Batbold said.

"We are hoping to reduce the current air pollution by 20 percent. Those poor households that burn raw coal will be given improved, efficient fuel to burn in their stoves. If people stop burning coal, air pollution will be reduced," said the mayor.

New migrants will be banned from settling in the city, and the existing rural migrants in the capital city will be given opportunities to return to the countryside, according to the Municipal decision.

Mongolia has six months of winter, and more than 300,000 households, or 800,000 residents, of Ulan Bator's slum districts have to rely on raw coal and other inflammable materials such as plastics and old rubber tires to keep warm and cook during this period.

As a result, Ulan Bator is now one of the most polluted cities in the world with a PM2.5 density on average seven times higher than the World Health Organization (WHO) standards.

The Mongolian government and international donors and development organizations, such as the World Bank and Asian Development Bank, have spent millions of U.S. dollars on programs and projects to reduce the city's air pollution since 2000.

However, analysts said that these efforts didn't substantially reduce the air pollution, which remained about the same as it was in early 2000.