NEW DELHI — Contrary to the defense minister's claim in parliament Tuesday that the Indian Air Force will acquire five firing units of the S-400 long-range surface-to-air missile (LRSAM) system between 2017 and 2022, one senior Ministry of Defence (MoD) official who requested anonymity says a budget crunch will prevent such a purchase for at least two years.

"Our priority is to clear the global buy of $8.9 billion for Rafale fighters, $1.5 billion for very short range air defense (VSHORAD) man-portable systems and $1.5 billion in short-range surface-to-air missile (SRSAM) systems. There is no money for other foreign purchases," the official said.

On Tuesday, Defence Minister Manohar Parrikar said the Defence Acquisition Council approved at its Dec. 17 meeting the purchase of the S-400 LRSAM systems along with associated equipment and missiles from Russia .

Five units of the Russian-made S-400 Triumf systems will cost $4.5 billion.

The S-400 Triumf system is capable of intercepting and destroying airborne targets at a distance of up to 400 kilometers (250 miles), and can simultaneously engage up to six targets.

The Indian Air Force (IAF) wants the S-400 systems to fill holes in its fledgling air defense strength and allow it to strike multiple targets, including ballistic missiles and stealth aircraft, a senior IAF official said.

"However, IAF has yet to conduct trials of S-400 systems in Russia," he said.