The United States says there is no banned list of Indians for US visas but those coming to "engage in scientific or technological activity" from any part of the world may require "additional screening".
A state department official declined comment on Indian media reports that MR Srinivasan, a member of India's Atomic Energy Commission, and R Chidambaram, the principal scientific adviser to the prime minister, has faced problems in getting a US visaas due to continuing American sanctions against India for its 1998 nuclear tests.
"We don't comment on individual cases. They are confidential," Jennifer Viau, a spokesman for the department's South and Central Asian Affairs Bureau, said on Friday.
However, "Under immigration policy travellers coming to the US to engage in certain scientific or technological activities require additional screening before being issued a visa," she said.
"This policy applies to applicants of all nationalities if they are travelling to the US to engage in certain scientific or technological activities," Viau added suggesting that it was not an India specific procedure.
Denying that Srinivasan and Chidambaram figured on a banned list of scientists for US visas as part of continuing American sanctions against India for its 1998 nuclear tests, she said, "We adjudicate visa cases only after an application is submitted. There is no banned list of Indians for US visas."
A report in The Telegraph had said that Srinivasan could not chair a scheduled meeting in Washington last week focussing on the India-US nuclear deal because the American embassy in New Delhi could not issue him a visa in time to travel to the US.
Similarly R Chidambaram, the principal scientific adviser to the prime minister, may face visa problems for coming to Washington for a meeting next week as he was on a banned list of Indians for US visas for an extended period for his direct role in the Pokhran tests in 1998, the report suggested.
In fiscal year 2006 ended Sep 30, 2006 as many as 437, 687 non-immigrant US visas were issued to Indian nationals. This is an increase over 378,039 visas issued in fiscal 2005, Viau said but was not aware of how many Indians were denied a visa.
US Assistant Secretary of State for South and Central Asia Richard Boucher has said that American diplomatic missions in India had "processed" a record 600,000 visas by August end this year.