Other trade groups, including those representing the pharmaceutical and manufacturing industries, echoed the call for a tougher stance on India.

India is on the US government's Priority Watch List for countries whose practices on protecting intellectual property Washington believes should be monitored closely.

The United States and India have been trying to get their relations back on track after New Delhi blamed Washington for a "mini crisis" over the treatment of its deputy consul general in New York in December.

The diplomat, Devyani Khobragade, was arrested and strip-searched after she was accused of visa fraud and underpaying her maid.

Her treatment provoked protests in India, which curbed privileges offered to US diplomats in retaliation and asked Washington to withdraw a diplomat from New Delhi.

Khobragade left the United States in January after a complex deal in which her diplomatic status was switched to the United Nations, affording her a greater degree of immunity from prosecution. But U.S. authorities have so far refused to drop the charges against her.