Congress president Sonia Gandhi on Monday wrote to Nepal's Prime Minister Sushil Koirala expressing grief and shock at the devastation caused by Saturday's massive earthquake.
"The tragic loss of thousands of lives and the enormity of the destruction has saddened us," she wrote.
"I myself and on behalf of the members of the Indian National Congress convey our heartfelt condolences to the people of Nepal."
She said the Congress "wholeheartedly supports the rescue and relief operations being undertaken by the Indian Air Force and Army".
"I take this opportunity to assure you of our continued solidarity with your government and support to the people of Nepal in this moment of crisis," she said.
Gandhi also expressed similar sentiments in a letter to former prime minister Madhav Kumar Nepal.