The US is in touch with India to address its concerns over the hike in H1-B and L1 visa fee, which would adversely affect Indian IT companies, a senior administration official has said.

"We are in touch with the Indian Government and are trying as best as we can to answer the questions they have about this new law," the official, familiar with the ongoing Indo-US talks on this issue, told PTI.

The official said there is no secret that the Indian government has expressed its concern about this new provision but Washington is not aware of India approaching the WTO on the issue.

"We are not aware that India has taken any action on the WTO front, but if and when they do that will be a question posed to US Trade Representative," the official said, responding to statements coming out from Indian officials that New Delhi might approach the World Trade Organisation.

However, there was no response from the USTR.

The Union Commerce and Industry Minister, Anand Sharma, had last week also written a letter to the US Trade Representative, Ron Kirk, in this regard.

Under the USD 600 million border security bill signed into law by President Barack Obama, nearly USD 550 million would be raised by increasing the fee in the categories of H-1B and L1 visas for the next five years, which would mostly impact Indian IT companies.

Businesses in India and the US have termed this as discriminatory and said this would undermine the growing Indo-US economic relationship, with which the Obama Administration does not agree.

Secretary of Homeland Security, Janet Napolitano, said last week that increase in the visa fee makes sense, but there is nothing in the bill that would have any adverse impact on the US-India relationship.

Indo-US ties, she said, is robust and strong, Napolitano said.

However, officials, privately do concede that the visa row has brought some sort of strain at least in the economic ties, which have been robust under the Obama Administration.

State Department Deputy Spokesman Mark Toner said the move could have an adverse impact on Indian companies but exuded confidence that the long-term economic partnership with India would continue to deepen and strengthen.

"We understand the Government of India's concerns. We realise it could impact Indian companies that invest in the US and we also understand the potential impact on Indians who work in the US as well as some American businesses," Toner said.