"At the moment the government has cleared the purchase of 126 aircraft. We are taking information from four countries, the United States, France, Sweden and Russia," Tyagi told reporters on the fringes of an aero-space seminar.

"We are seeking information (on various aircraft). It could be single engine or twin engine (jets). The field is right open," said Tyagi who took the top job last month.

"Once we get the information, we will go ahead and seek requests for proposals. We will study those proposals and carry out a technical evaluation ... Then we will do commercial negotiations," he said in this southern IT showcase city.

All the aircraft would be bought from a single manufacturer, he said adding," We cannot buy half from one and half from another because it increases our difficulties."

France's Dassault and US giant Lockheed have long been considered frontrunners to upgrade the Indian air force.

The Indian Air Force (IAF) has about 1,500 aircraft, but has lost a number jets, particularly Russian-made MiG-21s, which have been nicknamed "flying coffins" in India.

Tyagi said there was no fixed timeframe for the acquisitions but, "as chief of air staff I want it today." He refused to put a price on the acquisitions.

"It's too early because each aircraft comes with a lot of systems, weapons, so I cannot even hazard a guess," he said.

The seminar precedes India's annual air show which opens in Bangalore on Wednesday. Lockheed Martin is showcasing F-16 fighters alongside Russia's Sukhois, MiG-29 and MiG-21 jets and Dassault's Mirage 2000.

The air chief said India's home-grown Light Combat Aircraft, whose development has been delayed by a decade due to US sanctions and technical difficulties, would also be flying with the IAF soon.

Last year, New Delhi decided to buy 66-advanced jet trainers from Britain in a deal worth more than a billion dollars which had been under negotiation since the 1980s.