The delay in the manufacture of indigenous NAG missiles has forced India to consider buying thousands of Javelin anti-tank guided missiles from the United States.

The Indian government would go down the route of a U.S. direct foreign military sale when ordering the Javelin, made by Raytheon and Lockheed Martin. The process could frustrate European, in particular Russian, ATGM manufactures because it bypasses the global competitive tender route.

Defense Minister A. K. Antony told Parliament that a letter-of-request had been sent to the U.S. government for procurement of the third-generation off-the-shelf Javelin. Included in the letter is a transfer of technology request that could mean the man-portable Javelin is made under license in India.

Antony gave no indication of numbers of missiles needed, nor of numbers to be made in India.

What is known, however, is the army's acknowledged shortfall of around 44,000 ATGMs -- half of their required number. The Javelin order could run into the thousands until the first, vehicle-launched version of the NAG, meaning "snake" in Sanskrit, is inducted into the army next year.

The third-generation NAG with a 2.5-mile range has been 20 years in development and is on the verge of entering production.

But the army first will be getting the largest, vehicle-launch version of the missile, nearly 6 feet long, 7.5 inches in diameter and weighing around 95 pounds.

Other plans for the NAG include a helicopter-launched version with a range of nearly 5 miles. Launch systems are planned for the armed HAL Dhruv and HAL light combat helicopters produced by state-owned Hindustan Aeronautics.

A 6-mile air-launched version will probably be set up for use by the air force's aging Anglo-French Jaguar fighters made by SEPECAT.

Also planned is a similar land version, to be launched from a hydraulically lifted mast. A man-portable version will be a direct competitor to the Javelin and weigh around 9 pounds, as against 26 pounds for the Javelin.

The army has ordered 443 NAG missiles and 13 Namicas, the missile's tracked carrier, the main tank-busting vehicle. The missiles are carried on the sides of the Namica for offensive operations.

Currently, infantry units are relying on two man-portable ATGMs. The second-generation French Milan is made by Paris's MBDA and has a range of just more than 1 mile. The Russian Konkurs ATGM, designed and made by Tula Machinery Design Bureau, has a range of around 2.5 miles.

Both of the wire-guided missiles are also produced under license in India by PSU Bharat Dynamics.

To help ease the shortfall of ATGMs , the army has ordered since 2008 around 4,100 of the advanced version Milan-2T missiles with tandem warheads and 15,000 Konkurs-M missiles.

The Javelin has been used by U.S. forces during bilateral battalion-level combat exercises, including the annual Yudh-Abhyas at the Indian army's Babina base, in the state of Uttar Pradesh, last October.