However, this has not deterred cooperation in civil nuclear area between India and countries like France and Russia.
Official sources said American companies were insisting on liability insurance for their involvement in India and that is being sorted out.
Once that is done, US companies will be setting up reactors in India, they said.
The sources pointed out that cooperation was on between India and other countries with nuclear capability and Memorandum of Understanding (MoU) have been signed with Russia and France.
New Delhi is also attaching a great deal of importance to the visit of US Secretary of State Hillary Clinton later this month, officials said.
They said relations with the US were progressing very satisfactorily, pointing out that Clinton has made some positive statements on India.
Describing her visit as a building block in the bilateral relations, the officials said the relations were being taken forward and there were no major hiccups in ties.
Clinton would be meeting Prime Minister Manmohan Singh and External Affairs Minister Pranab Mujherjee during the visit.
"It is a very important and very crucial visit in terms of bilateral relations," they said.
