Washington, Jul 21 (IANS): Eyeing India's expansive multi-million dollar military modernisation programme, two top US lawmakers have asked the Pentagon to develop a closer defence relationship with New Delhi, including potential co-development or co-production of military weapon systems.

In a letter Friday to deputy defence secretary Ashton B Carter, who is visiting India next week, Senators John Cornyn and Mark Warner, co-chairs of the Senate India Caucus, said it is in the interest of both the US and India to continue building a strategic and military culture of cooperation between the two countries.

With 38 Senators, the Senate India Caucus is the largest country-specific caucuses in the US Senate.

"As India undertakes its expansive military modernisation programme - projected to cost an estimated $80 billion by 2015 - numerous prospects exist for the US to further expand defence trade and cooperation with India," wrote Republican Cornyn and Democrat Warner.

"Recent US arms sales have benefitted the US and India alike, increasing commonality of military equipment platforms, providing expanded opportunities to conduct joint military exercises, and contributing to security in the Indo-Pacific region," the lawmakers said.

"With these interests in mind, and with the goal of further expanding US-India defence trade, we encourage you to actively engage with your Indian counterparts to develop ways to improve the compatibility of the defence acquisition systems of the United States and India," they said.

Cornyn and Warner stressed that it is in the interest of both the US and India to continue building a strategic and military culture of cooperation between the two countries.

"We see the partnership between our two democracies as critical to the maintenance and expansion of a rules-based international system that promotes freedom, democracy, security, prosperity, and the rule of law in the 21st century," they wrote.