Observing that the talks on the nuclear deal was a "complicated" issue as it entailed changing the "world architecture" in the field, the US Monday said "every effort" is being made to conclude the deal before President George W Bush [Images] arrives here on Wednesday.

US Ambassador to India [Images] David C Mulford said though the civil nuclear deal was a very important in the Indo-US ties, it was one among many issues of cooperation between the two countries.

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"In the last few weeks, there have been a series of meetings and negotiations. These continue," he said two days after US Under Secretary of State Nicholas Burns concluded the third round of negotiations with Foreign Secretary Shyam Saran on implementation of the July 18-deal.

Mulford told reporters that the negotiating atmosphere has been positive. "But, of course, this is a very complicated area. Both the countries are breaking new ground." He said the progress is continuing and "we are hoping we can reach the agreement by the time the President visits here and every effort is being made to do so."

If the deal does not come through by the time of the visit, the negotiations will continue after that, he said. Refusing to go into the specifics of the negotiations, the envoy said the talks are covering every aspect of the deal. The two sides have acknowledged that differences remained on various aspects involving the deal but asserted that both were committed to continue the dialogue.

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