WASHINGTON: India has sent a letter of request (LoR) to the US seeking to purchase patrol drones for protection and vigilance of its maritime assets in the Indian Ocean, sources said.

The letter of request (LoR) sent by New Delhi last week comes less than a fortnight after India was inducted into Missile Technology Control Regime (MTCR) and recognised by the US as a "major defence partner" after the meeting between Prime Minister Narendra Modi and President Barack Obama, earlier this month.

This is part of Modi Government's effort to fast track its goal to secure the country's maritime assets particularly in the Indian Ocean and detect any untoward intrusion like Mumbai terrorist attack.

The letter seeks purchase of state of the art multi mission maritime patrol Predator Guardian UAV's (Unmanned Aerial Vehicle) from General Atomics, they said.

Flying at an altitude of 50,000 feet these drones have the capacity to fly non-stop for more than 24 hours and monitor the movement of objects as small as a football, sources said.

India had previously shown interest in purchasing these drones from the US, but the Obama administration was unable to process these request as India was not a member of MTCR.

"Earlier this month, President Obama and Prime Minister Modi affirmed their support for US-India cooperation in promoting maritime security," they said.

The issue of drones was discussed by the Prime Minister with President Obama who gave a favourable response.