"We're not in a position to speculate on its conclusions," State Department spokesperson Jen Psaki told reporters when asked about a report in IHS Jane's, a leading defence and security publication.
"Nothing we provide to India, under the civ-nuke agreement, may be used to enhance India's military capability or add to its military stockpile," she said.
"But we don't have enough information or confirmation of the report to speak to that."
HIS Jane's had reported that new units at the Indian Rare Metals Plant near Mysore would boost India's ability to produce weapons-grade uranium to twice the amount needed for its planned nuclear-powered submarine fleet. The expansion could potentially support the development of thermonuclear weapons with the facility likely to become operational by mid to late 2015, the publication said, basing its findings on analysis of satellite imagery and public statements by Indian officials.
"We remain fully committed to the terms of the 123 Agreement and to enhancing our strategic relationship," Psaki said referring to the 2008 landmark India-US civil nuclear deal that ended New Delhi's nuclear isolation.
When reminded that military facilities were explicitly excluded from the Indian civil nuclear agreement, she repeated: "Well, my understanding of it is that nothing provided to India can be used to enhance their military capability.
"I'm not certain - obviously, that would be high speculative about this, given there's only one external report that's not a reflection of a US Government report," Psaki said.