NEW DELHI: India has finalised the plan to acquire 30 weaponised Sea Guardian (or Predator-B) drones in yet another proposed mega defence deal with the US, even as New Delhi remains steadfast about going ahead with its deal inked for the Russian S-400 Triumf missile systems despite mounting pressure from the Trump administration.Top sources say the tri-service procurement proposal for the Sea Guardian remotely piloted aircraft - with 10 drones each for the Navy, IAF and Army to hunt and destroy targets on land and sea - is now "being vetted" before it is sent to the Defence Acquisitions Council (DAC) for approval.Once this "acceptance of necessity" is granted by the DAC, India will issue "the letter of request" to the US for the government-to-government deal under Pentagon's foreign military sales programme. "Several rounds of bilateral discussions have already taken place. It should take about a year for the actual contract to be inked," said a source. India is already in an advanced stage to acquire 24 naval multi-role MH-60 "Romeo" helicopters for $2.6 billion and the National Advanced Surface-to Air-Missile System-II for almost $1 billion, with the contract for the former set to be inked by September-October.With the US having already bagged military contracts worth $17 billion from India just since 2007, while also remaining in contention for several other major projects, Delhi is upset with Washington's intransigence over the $5.43-billion deal inked for the S-400 systems with Russia in October 2018. India has made it clear that it has "no plans to scrap" the S-400 deal , as was reported by TOI last week.The acquisition of the "hunter-killer" Sea Guardians, with advanced ground control stations, launch and recovery elements, air-to-ground missiles, smart bombs and the like, will be a huge capability upgrade for the Indian armed forces."The platform will be the same for the Army, Navy and IAF, while the payloads can be tweaked a little to suit individual service requirements," said another source.Much like fighter jets, armed drones are capable of firing missiles and precision-guided munitions on enemy targets before returning to their home bases to re-arm for the next mission. With a greater flying endurance than fighters, they can undertake long-range intelligence, surveillance and reconnaissance missions as well as silently hover over targets before letting loose their missiles.The Navy, for instance, can deploy the Sea Guardians to monitor "choke points" from the Persian Gulf to Malacca Strait in the Indian Ocean Region . The Sea Guardians, which have a maximum range of 5,500 nautical miles with an endurance of 35 hours for ISR missions, will greatly help to enhance India's overall maritime domain awareness in its strategic backyard.India's inking of the bilateral military pact with the US called Comcasa (Communications, Compatibility and Security Arrangement) in September 2018 has paved the way for greater access to advanced military technologies with encrypted and secure communications and data links.The Sea Guardian, for instance, has Comcasa-protected equipment like an advanced GPS, identification friend or foe receiver and VHF system, which is immune to jamming and spoofing from enemies.