At least 17 people have been killed by heavy rains and flooding in Assam, while at least 14 people have died in Bangladesh, with millions of people also displaced, officials said on Saturday.
Although rainfall had decreased as of Saturday, officials in Assam, a tea-growing and oil-rich state, added water levels across rivers were still overflowing.
"Overflowing rivers are flooding new areas, making things worse," said Keshab Mahanta, Assam's water resource minister.
Home Minister Rajnath Singh is in Assam making an aerial survey and holding discussions with state officials about relief efforts.
The home minister will be accompanied by minister of state for home, Kiren Rijiju and minister for ministry of development of north eastern region Jitendra Singh and will take stock of the situation in the districts of Nagaon and Morigaon besides the Kaziranga national park.
He will also be visiting Bhagatgaon camp of flood-affected people in Morigaon district, an official release said.
Authorities in Assam have opened more than 800 temporary shelters and food and medicines distribution centres across the state, a senior official at the state disaster management authority said.
Flooding is an annual problem during the monsoon season in South Asia, but the impact has been worsened by crumbling civic infrastructure, clogged drains and uncontrolled urban expansion.