Cameron at a meeting here on the margins of the G-20 summit.
External Affairs ministry spokesman Vishnu Prakash, briefing reporters on the meeting, recalled that Britain had earlier supported India's case for non-permanent membership of the UNSC.
The Prime Minister and Cameron had been meeting regularly even before the latter's state visit to India recently.
The two had met in Toronto in June after his election as Prime Minister of Britain and in 2006 when he had come to New Delhi after his election as leader of the opposition.
The spokesman said the two countries shared a strategic partnership from 2004 which was converted into an enhanced partnership during Cameron's visit in July.
UK has been India's major trading partner with trade at USD 11 billion and British investment in India placed at USD 6 billion.
Britain is the fourth largest investor in India.
The India-UK CEO's forum, co-chaired by Ratan Tata and Peter Sands, Chairman of the Standard Chartered Bank, has been activated and it formed the bed rock of the bilateral economic relationship.
The Prime Minister also met Prime Minister of Ethiopia Meles Zanawi and Mexican President Felipe Calderon.
Zenawi was appreciative of the excellent support India gave in the area of hi-tech programme as New Delhi proposed to set up a vocational training institute in Ethiopia.
He also spoke of India's development partnership with Africa which is a model that can be followed elsewhere.
The two leaders spoke about the first India-Africa summit that was held in Delhi in 2008 and the second summit that is to be held in Africa next year.
The venue and dates are yet to be decided.
The Ethiopian Prime Minister invited Singh to visit his country which he accepted.
Ethiopia and India has a long shared relationship and Addis Ababa has been supportive of India's quest for permanent membership of the UNSC. Recently it backed India in the voting for the non-permanent membership of the UNSC and the reforms of the UN.
At the meeting, it was conveyed to the Ethiopian Prime Minister that the EXIM bank of India has decided to set up its representative office in Addis Ababa.
It was also agreed that India would consider Ethiopia's request to help in the construction of a railway line between Addis Ababa and Djiboti.