Officials of India and the US have met in London as part of efforts for early conclusion of bilateral agreement to operationalise civil nuclear deal and reported 'further progress'.

At the two-days of technical-level talks on 123 Agreement, which ended on Tuesday, India clarified 'certain concepts' and the two sides agreed that further discussions were required to sort out the remaining differences.

"We clarified certain concepts and exchanged ideas making further progress towards a mutually-agreed text," External Affairs Ministry spokesman Navtej Sarna told reporters when asked about the meeting.

He said the two sides agreed that some further work was required to 'bridge the remaining gap' and the discussions will continue.

At the talks that focussed on technical details governing the proposed agreement, the two sides were represented by officials of the respective nuclear establishments.

The meeting assumes significance as it comes after US Under Secretary Nicholas Burns put off his visit, planned for this month, to 'finalise' the agreement.

Conclusion of the agreement has been delayed due to differences between the two sides on issues like reprocessing right, perpetuity of fuel supplies and continuance of the civil nuclear cooperation if India were to conduct an atomic test.

The issue is expected to be discussed at the highest level early next month when Prime Minister Manmohan Singh meets US President George W Bush in Germany on the sidelines of the G-8 Summit.