The rejection can be considered as a violation of ICAO or International Civil Aviation Organization charter.
Even as Pakistan has denied an overflight to Prime Minister Narendra Modi's flight, India has said it, "hopes (Pakistan) will realise the folly of its actions".
Calling Islamabad's action as "unfortunate", foreign secretary Vijay Gokhale in response to a question said, "as far as going to an international organisation is concerned, it will take look at that. So far there is no intention to do so. If they are in violation of the regulation of civil aviation organisation, that is a possibility we can certainly consider".
The rejection can be considered as a violation of ICAO or International Civil Aviation Organization charter. Under the charter, unless its war, denying the use of airspace by singling out cannot be done by any country.
New Delhi can take Pakistan to ICAO where the country can be slapped with a heavy fine.
This is the second time in a month that Pakistan has denied an overflight to an Indian VVIP. Earlier this month, Islamabad denied permission to President Ram Nath Kovind's plane during his Europe visit.
On Wednesday, strongly reacting to Islamabad's decision, Ministry of External Affairs spokesperson Raveesh Kumar said, "Pakistan should reflect upon its decision to deviate from well established international practice, as well as reconsider its old habit of misrepresenting the reasons for taking unilateral action."
PM Modi will be in the United States from September 21 to 27 for big-ticket events like the diaspora event in Houston and the address to United Nations General Assembly.