A top US diplomat has said a bilateral investment treaty, BIT, currently being negotiated, is critical for deepening Indo-US economic ties, and asserted that the US is committed to work with India to fully unlock the true potential of the businesses.Assistant Secretary of State for South and Central Asia, Nisha Desai Biswal said in her key note address to the FICCI-IIFA Global Business Forum being held in Tampa on the sidelines of the IFFA Awards this weekend, Biswal said that a target of 500 billion US Dollars in bilateral trade is entirely possible. The bilateral trade between the two countries has now reached 100 billion US Dollars.Nisha Desai Biswal is the first Indian American to be made in charge of the South and Central Asia.