Members of the Tamil National Alliance met with US Ambassador-at-Large for War Crimes Issues, Stephen Rapp, who is on a 4-day visit to Sri Lanka.
Mr Rapp and TNA leader R. Sampanthan and MP M A Sumanthiran held discussions relating to the issues faced by Tamils on the island.
The visit comes as the US is gearing up for the UN Human Rights Session in Geneva later this month.
The US is thought to be preparing a resolution against Sri Lanka and is actively engaging with other countries garnering support for it.
Senior US officials Robert Blake and Maria Otero are also due to visit Sri Lanka later next week.