US ambassador to India Nancy Powell has said India is poised to sign an additional $8-billion worth sales in direct commercial and foreign military sales from the US.Speaking to the members of the Indo- American Chamber of Commerce in Chennai today, the US ambassador said with the sale of transport aircraft C-17 and C-130J, the total foreign military sales had doubled. Referring to the trade relationship, she said the US was concerned in the ongoing challenges to trade and investment, including high tariff and non tariff barriers, restrictions on foreign investment, lack of transparency and defence offset requirements.Ms. Powell referred to the recent meeting of Finance Minister Pranab Mukherjee with US Treasury Secretary Geithner in implementing policies, which would reassure foreign investors that India would continue to welcome foreign capital by advancing important economic reforms. On the development activities in the US, she said the country was looking forward to better ties with progressive states like Tamil Nadu, Karnataka, Haryana, Rajasthan and Gujarat.