Stating this, the Environment Ministry also told the top court that several key issues relating to steps to curb air pollution were under its "active consideration" and details have been sought from all states and union territories in this regard.

The ministry told a bench of Justices Madan B Lokur and Deepak Gupta that on the issue relating to import of pet coke, they have received responses from the Ministry of Petroleum and Natural Gas (MoPNG) and the Directorate General of Foreign Trade (DGFT).

"MoPNG has said we should consult the DGFT. We have communicated to the DGFT and they have also responded. The MoEFhas to take a view. Ban (on pet coke), if done, will be for the whole country," Additional Solicitor General A N S Nadkarni, representing the Ministry of Environment, Forest and Climate Change (MoEF&CC), told the bench, adding that the exercise would take three to four weeks.

He said the MoPNG has suggested that the use of pet coke should be discouraged and the industries should be asked to switch over to alternate environment-friendly fuels.

The bench then listed the matter for hearing after six weeks while noting the submissions of the ASG, who also said that "the matter is under active consideration of MoEF and information and statistics have been sought from all the states and UTs".

Advocate Aparajita Singh, who is assisting the court as an amicus curiae in the matter, raised several issues, including finalisation of pollution emission standards for five categories of industries.

The amicus said the Centre had earlier said that for five categories of industries, the emission standards would be finalised by March 31.

Regarding the issue of strengthening power distribution in the national capital region (NCR), Singh said there was power surplus in the region but the issue was of distribution. Besides, the use of generators was a cause of pollution.

The amicus also raised the issue of a comprehensive action plan for control on air pollution in other cities with high pollution.

However, the ASG said that several things have already been done and the remaining steps would also be taken soon.

The bench asked the ministry to file a comprehensive status report giving details of all the issues within three weeks.

The environment ministry had earlier told the apex court that a National Clean Air Programme (NCAP) to comprehensively deal with the rising air pollution levels across the country would be finalised soon.

NCAP is a medium term national level strategy to tackle the increasing air pollution problem in a comprehensive manner and its overall objective includes evolving effective ambient air quality monitoring network across the country.

The court had earlier asked the Centre to look into the problem of air pollution on a nationwide basis and not confine it to Delhi-NCR only.

The court is hearing a PIL filed in 1985 by environmentalist M C Mehta who had raised several issues relating to air pollution in the Delhi-NCR.