As India and the United States race against time to implement the civil nuclear deal, officials on Saturday indicated that the two countries could hold one more round of talks before President George W Bush [Images] travels to New Delhi.

"There is nothing specific as of now but nothing can be ruled out," an official told PTI when asked whether Under Secretary of State Nicholas Burns could travel to India to hold talks with Foreign Secretary Shyam Saran on the nuclear deal.

Burns' trip could be in the context of preparations for Bush's visit but there are indications that the two sides could discuss the nuclear issue as well.

The two countries had intended to implement the deal, signed on July 18 last year during the US visit of Prime Minister Manmohan Singh [Images].

However, after two rounds of talks between Saran and Burns, they acknowledged that there were 'difficulties ahead'. After the talks on January 20, both countries had indicated that the deal could not be implemented before the Bush visit.

"We have made some progress over the last six months (of negotiations) but a lot more has to be made. There are difficulties ahead," Burns had said.

Asked whether negotiations could be completed before the Bush visit expected in the first week of March, he said "We are not sure. We are going for it. We will be working hard but there are difficulties there."

The talks have apparently become difficult because of India's reluctance to accede to the US desire that New Delhi put fast breeder reactors in the civilian side.

Complete coverage: The Indo-US nuclear tango