US ambassador to India David C Mulford today emphasised the need for New Delhi to expedite what it had voluntarily committed to do in the landmark joint statement by PM Manmohan Singh and President George W Bush in Washington.Mulford’s statement comes a day before Under Secretaries of State Nicholas Burns and Robert Joseph begin submitting their testimony to the US Congress on supply of civilian nuclear technology to India.Asked by The Indian Express about the concerns facing the two countries at this juncture, Mulford said, ‘‘Commitments need to be kept in this agreement. We are in the process of trying to change the legislation, but we have to do it in a fashion that maintains our commitment to non-proliferation in other parts of the world. We need to find a way to accommodate this in the international architecture. It is complex, but it is a must.’’Earlier, after a talk organised by a local public policy thinktank here, Mulford was firm that ‘‘unhelpful public statements’’ and ‘‘posturing’’ would only serve to make an already difficult process even more so.He indicated that the US Congress was also closely watching India’s commitment to separating its civilian and military nuclear facilities. Washington has hinted that India’s efforts on the process of separation have been ‘‘minimalist’’, pushing maximum facilities under the definition of military use.The Bush Administration is also understood to have made an appeal to New Delhi to assist in the overall lobbying process. Capitol Hill will also be watching closely India’s stand on September 17 at a meeting of the IAEA, on Iran’s nuclear programme.Pentagon briefingA top level team from the Pentagon, led by DSCA chief Lt Gen J B Kohler today gave a ‘‘highly classified’’ briefing on the Patriot-3 missile defence system, the F-16 and F/A-18 fighters to top officials of South Block and the armed forces today. The presentations, said to be of a highly technical nature, will continue tomorrow, with representatives of the Department of Defence and defence contractors accompanying Kohler.