India's decision to join the "core group" was conveyed in conversations US President George W. Bush and Secretary of State Colin Powell had with Indian Prime Minister Manmohan Singh and Foreign Minister Natwar Singh, a ministry statement said.

Bush had proposed on Wednesday that the United States, Australia, Japan and India form a "core group" to "avoid duplication of efforts, identify gaps in the relief process and find ways and means to address these deficiencies," the statement said.

On Thursday India's foreign secretary Shyam Saran held a teleconference with officials from the United States, Australia and Japan.

"The foreign secretary acquainted the other members of the group with the relief and rescue efforts already launched by India for Sri Lanka and Maldives," two other countries battered by the tsunamis on Sunday.

The Indian government says it has sent warships, helicopters and aircraft to distribute food, medicines and blankets to neighbouring Sri Lanka and the Maldives and has promised over 23 million dollars in monetary aid.