The National Green Tribunal (NGT) today asked five northern states to clarify their stand on plying and registration of Bharat Stage-I and Bharat Stage-II vehicles which have been banned in Delhi-NCR. <br/><br/>NGT Chairperson bench asked the Uttar Pradesh, Haryana, Rajasthan, Punjab and Himachal Pradesh governments to clearly state by tomorrow if they were prepared to accept these vehicles in their areas.<br/><br/>The green panel also slammed the states for delay in identifying no-pollution-zones in their areas for plying of de-registered diesel cars which have been barred from running in the national capital region.