Buoyed by the successful test- firing of the Agni-4, DRDO will launch the 5,000-km version of the nuclear capable missile after three months as part of strengthening India's deterrence capabilities.

"Agni-V is presently undergoing integration and we may test fire it by the end of February next year. It is right on schedule and the successful test of Agni-4 will prove to be a building block in development of this missile," DRDO chief V. K. Saraswat said here on Wednesday.

Addressing a press conference here, Saraswat talked about India's missiles programme and developing effective deterrence capability against adversaries. on Tuesday, DRDO had successful test fired nuclear capable Agni-4 missile from a test range in Wheeler Island off Odisha coast.

"Agni-4 belongs to DRDO's flagship programme to make the country self-reliant in missile technology. We have now graduated to a higher level of missile technology with more capable versions of the earlier missiles such as Agni-1 and Agni-2," he said.

Talking about Agni-4's capabilities, he said, "Earlier missiles were based on rail mobile launchers which needed an exhaustive infrastructure support. But Agni-4 is based on road mobile launchers. It gives a much higher level of flexibility and is a maintenance free system. It is better in terms of accuracy and performance as well."

This missile is better than previous ones in various meters such as terminal accuracy, payload delivery capability and also in terms of maintenance and flexible operational deployment, he said.

On comparison with the missiles developed by China and US, Saraswat said Agni-4 belongs to the category of one of the best missiles in the world.

"This missile compares with the best in the world today in terms of all technologies whether it is Pershing (American), Chinese DF-31 or any other missile in the world," he said. Along with other features, Agni-4 will be 'immune' from counter-measures developed by the adversaries.

"Agni-4 is just 20 tonne missile with a smaller payload. It will leave a very small radar signature which makes it immune to the counter measures developed by the enemy. Its previous version Agni-3 was a 48 tonne missile with a payload of more than five meters length," Saraswat said.

The DRDO chief said that the premier research organisation was now working on missiles which will have capability to beat the anti-ballistic missile shield of the adversaries and has achieved 'significant success' in this regard.

Noting that the missiles will undergo two more repeatable tests, Saraswat said it would be ready for user trials by 2013.

"Efforts are on to conduct two more repeatable test of the missile before we go for production. But there will not be any delay because of the repeatable tests as the production line is already established. We are planning to complete the test by 2012 so that the user trials can begin by 2013," he said.

On Agni-5, he said, "It will have advance mechanical control and navigation systems. It will be an advancement of the technology used in Agni-4 which was tested yesterday. Just like Agni-4 it will be a high performance and maintenance free system."