"The time has come to take a holistic view to find a permanent, medium and long term solution to the flood problem in India," Singh told reporters in northeastern Assam state's main city of Guwahati after an hour-long aerial survey of floods which have displaced about 11 million Indians.

He said he had set up a "high-power task force" which is to submit a report on "strategies to control floods on a permanent basis" within six months.

Singh's one-day trip came as the death toll due to flooding caused by monsoon rains since mid-June in India touched 217, after another three deaths were reported overnight in Assam and another 21 in neighbouring Bihar state.

"I have realised the gravity of the situation after making an aerial survey and the situation is really devastating," Singh said.

The prime minister said New Delhi would discuss with neighbours China and Bhutan claims that floods in India were aggravated by the two neighbours releasing excess waters from their dams upstream.

Singh was responding to a query on a letter sent to him by Assam Chief Minister Tarun Gogoi stating China and Bhutan had released excess waters from their dams, aggravating the flooding of Assam's main Brahmaputra river.

"Incidents like flooding have always been (inter-country affairs) and if required we will have to discuss the problem with the two countries," Singh told reporters.

According to the Assam chief minister, the melting of snow in the upper reaches of China's Tibet region had also contributed to the already-critical situation in the state.

The Assam government has described the current flooding in the region as "the worst" in 25 years and demanded 21.56 billion rupees (479 million dollars) as immediate financial assistance from New Delhi.