India's ties with Nepal are "unparalleled", Prime Minister Narendra Modi said on Sunday, a day ahead of his visit to Lumbini in the neighbouring country on the occasion of Buddha Purnima.

In a statement, Modi said he was looking forward to meeting Nepalese Prime Minister Sher Bahadur Deuba again after their "productive" discussions during his visit to India last month.

He said both sides will continue to build on the shared understanding to expand cooperation in multiple areas, including in hydropower, development and connectivity.

"Our ties with Nepal are unparalleled. The civilisational and people-to-people contacts between India and Nepal form the enduring edifice of our close relationship," Modi said in his departure statement.

"My visit is intended to celebrate and further deepen these time-honoured linkages that have been fostered through centuries and recorded in our long history of inter-mingling," he said.

The prime minister is paying a day-long visit to Lumbini on Monday on the occasion of Buddha Purnima. It will be the prime minister's fifth visit to Nepal since 2014.

"I look forward to offering prayers at the Mayadevi Temple on the auspicious occasion of Buddha Jayanti. I am honoured to follow in the footsteps of millions of Indians to pay reverence at the sacred site of Lord Buddha's birth," Modi said.

Modi and Deuba will hold talks in Lumbini with a focus on further expanding cooperation in multiple areas including hydropower and connectivity.

"I also look forward to meeting Prime Minister Deuba again after our productive discussions during his visit to India last month," Modi said.

"We will continue to build on our shared understanding to expand cooperation in multiple areas, including in hydropower, development and connectivity," he added.