The United States said on Friday it was frustrated at the pace of negotiations with India on a civil nuclear cooperation agreement and will try to break the impasse in talks that begin later this month.
US and Indian negotiators are trying to complete an agreement affirming landmark political commitments announced by the two governments in 2005 and 2006 that would let India buy US nuclear fuel and reactors for the first time in 30 years.
But New Delhi has balked at provisions Washington considers essential, including a US legal requirement that it halt nuclear cooperation if India tests another nuclear weapon, US officials have said.
"There is frustration," said State Department spokesman Sean McCormack.
US Undersecretary of State Nicholas Burns and Indian Foreign Secretary Shiv Shankar Menon will discuss the matter in Washington on April 30 and May 1.
"They're going to explore ways that we can energize the discussions so that we can get this done," McCormack added, saying the State Department believed the agreement will ultimately be carried through.
While he declined to go into detail about the differences, McCormack said India had asked the United States to change some of its laws, something he ruled out.
The deal aims to overturn a three-decade ban on nuclear trade between the countries and help India meet its soaring energy needs even though New Delhi has not signed the Non-Proliferation Treaty and has tested nuclear weapons.
The pact was approved by the US Congress in December but the countries have since struggled to negotiate a bilateral agreement that lays down the terms of nuclear trade.
Apart from the restrictions resulting from another nuclear test, US officials have said India has rejected several other constraints, including US control over the use India makes of uranium or reactor fuel supplied by the United States.
This is intended to prevent India from enriching uranium or reprocessing spent fuel rods to extract plutonium for weapons.
But with the potential of India's nuclear market seen at $100 billion, some Indian experts said they suspect Washington is more keen to ensure India does not become independent of US uranium supplies and technology.
Indian officials and experts close to the negotiations said the conditions were politically and economically stifling to New Delhi.
Indian Prime Minister Manmohan Singh is under strong pressure from allies and the Opposition who don't want him to succumb to US pressure.