Officials in Agra, where US President Donald Trump is due to visit the Taj Mahal alongside Prime Minister Narendra Modi later, have pumped fresh water into the river which runs past the iconic ivory-white mausoleum to ensure it doesn't smell.

Nearly 17 million liters (4.5 million gallons) of water has been released from a stream in Mathura, north of Agra, to flow into the Yamuna river.

"When the water is stagnant a smell starts to develop, so we released the water to help the circulation so that the smell disperses. Big guests are coming so our state needs to make a good impression, it is important to welcome our guests properly" said Rajiv Rathi, executive engineer environment department of Agra Municipal Corporation.

"This is routine, you can put in a request to direct the water two days prior, there won't be a shortage upstream."