New Delhi, Sep 4 - Key differences still remain between rich economies like the US and advanced developing nations like India, China and Brazil, said World Trade Organisation (WTO) Director General Pascal Lamy here Friday.

'The US is ready to even clinch a final deal, but that may not exactly be the Indian view or a Chinese view or the Brazilian view,' Lamy said at an interactive session organised by the Confederation of Indian Industry (CII) here, after the conclusion of the two-day mini-ministerial meeting among representatives of some 40 key WTO members.

'But there remains tough nuts to crack during these negotiations,' Lamy said, hinting at the possibility of a tough stand that the advanced developing countries may adopt.