The U.S. Treasury has banned a Sri Lankan charitable organization it says has raised money for Tamil Tiger rebels fighting for an independent homeland.
The Treasury said it has designated the Tamil Rehabilitation Organization as a terrorist support group.
That designation freezes the groups' assets in the United States and bars Americans from making any transactions with it.
Treasury accuses the group of raising funds in the United States for Tiger rebels through a network of individual representatives.
The U.S. government branded the Sri Lankan rebels a terrorist group in 1997.
The Tigers have waged a nearly 25-year civil war against the Sri Lankan government that has killed some 70,000 people, including about 5,000 in the two years since a peace process collapsed.
The Sri Lankan government has recently begun a new offensive to drive the rebels from a northwestern district, having already ejected them from their strongholds in the east.
Rebels say they are fighting for an independent state for minority ethnic Tamils in Sri Lanka's north and east.
Some information for this report was provided by AFP and Reuters.