The Yuan Wang 5 is en route from the Chinese port of Jiangyin and due in the Chinese-run Sri Lankan port of Hambantota on Thursday, according to analytics website MarineTraffic.
It is described as a research and survey vessel, but according to an Indian media report, it is a dual-use spy ship, employed for space and satellite tracking and with specific usage in intercontinental ballistic missile launches.
Indian media reports said that New Delhi was worried the vessel would be used to spy on its activities and that it had lodged a complaint with Colombo.
India remains suspicious of China’s growing influence in its southern neighbour Sri Lanka.
India’s foreign ministry last week said that it will closely monitor “any bearing on India’s security and economic interests and take all necessary measures to safeguard them”.
In a written request, the Sri Lanka foreign ministry told the Chinese embassy in Colombo not to go ahead with the visit, an official involved in the process told AFP on Saturday.
“The ministry wishes to request that the arrival date of the vessel Yuan Wang 5 in Hambantota to be deferred until further consultations are made on this matter,” the request says.
Sri Lankan President Ranil Wickremesinghe assured political party leaders on Friday that the controversial visit will not go ahead as planned.
Earlier this week, Colombo appeared to brush aside Indian concerns, saying the vessel was coming only to refuel and replenish supplies and would not undertake any work in Sri Lankan waters.
India objected strongly when two Chinese submarines berthed in Sri Lanka in 2014.
Former president Gotabaya Rajapaksa, whose brother Mahinda Rajapaksa borrowed heavily from China while president from 2005 to 2015, was forced to resign last month over Sri Lanka’s worst-ever economic crisis, which is ongoing.