Putting pressure on Pakistan, the United States today said it is important that swift and stringent punishment should be slapped by Islamabad on six Mumbai terror attack suspects, including LeT founder Hafiz Saeed.<br/>The US Ambassador Timothy J Roemer told reporters after a meeting with the Home Minister Mr. P Chidambaram in New Delhi that it is important for the US and India that action is taken against the LeT founder and terror infrastructure in Pakistan is dismantled .The US envoy's comments came ahead of the meeting of Foreign Ministers of India and Pakistan in New York on the margins of the UN General Assembly session. AIR correspondent adds that the External Affair Minister Mr. S M Krishna is expected to convey New Delhi's disappointment to his Pakistani counterpart Shah Mehmood Qureshi over dithering in prosecuting the Mumbai terror accused. While Pakistan has been insisting on early resumption of the dialogue process stalled since November last year, India has firmly stated that this was not possible till Pakistan acted against the perpetrators of the 26/11 attacks.<br/>Meanwhile the US ambassador later met Prime Minister Manmohan Singh and discussed the forthcoming G-20 summit of leaders of the world's 20 biggest economies in Pittsburgh in the US next week. This was the first meeting of Roemer with the Prime Minister after he assumed charge last month. PMO sources said the envoy discussed with the Prime Minister the summit scheduled on September 24-25.