The Prime Minister inaugurated the memorial by lighting the eternal flame and laying wreaths.
Addressing ex-servicemen before the dedication of the National War Memorial to the nation, Modi said the armed forces and national security suffered due to criminal negligence before his government came to power in 2014, in an attack directed at the Congress.
Modi said the previous dispensation put "the family first" while for him it was India first. He said this while referring to the long delay in construction of the memorial mooted decades ago.
The delay by previous governments in construction of national war memorial was an injustice to families of fallen soldiers, he said. The Prime Minister said crucial decisions related to defence procurement and strengthening the armed forces were pending but his government cleared them on priority basis.
Addressing the ex-servicemen, he said the government will set up three super-specialty hospitals for them. On the Rafale deal, Modi said attempts are being made to stop arrival of the fighter aircraft aircraft but they will come to nought once the jets start flying in months.
Since Independence, more than 25,000 personnel have been martyred during the Indo-China War in 1962, the Indo-Pakistan wars in 1947, 1965 and 1971, the Indian Peace Keeping Force operations in Sri Lanka and the conflict in Kargil in 1999.
The National War Memorial also commemorates the soldiers who participated and made supreme sacrifices in United Nations peace-keeping missions, Humanitarian Assistance Disaster Relief (HADR) operations, counter insurgency operations and Low Intensity Conflict Operations (LICO).
Built at a cost of Rs 171 crore, the memorial has a 15.5 metre tall obelisk with an eternal flame and 16 circular walls of honour on which names of 25,942 martyrs have been carved in golden on granite tablets. The pattern of the walls symbolise the ancient Indian war formation "Chakravyuh".
The design of the memorial has a layout comprising four concentric circles, namely the "Amar Chakra" or Circle of Immortality, the "Veerta Chakra" or Circle of Bravery, the "Tyag Chakra" or Circle of Sacrifice and the "Rakshak Chakra" or Circle of Protection.
The memorial complex includes the central obelisk, an eternal flame and six bronze murals depicting the famous battles fought by the Indian Army, the Air Force and the Navy in a covered gallery.
The outermost circle, the Rakshak Chakra, comprises rows of more than 600 trees, representing the soldiers who guard the territorial integrity of the nation.
The busts of the 21 Param Vir Chakra awardees have been installed at the Param Yoddha Sthal and include those of three living awardees - Subedar Major Bana Singh (retd), Subedar Major Yogendra Singh Yadav and Subedar Sanjay Kumar.
The proposal for creating a National War Memorial was under consideration since early 1970s. The Union cabinet cleared it in October 2015 while the sanction for the construction at India Gate was issued on December 18 the same year.
(With inputs from agencies)