The issue of granting India access to Lashkar-e Taiba operative David Headley is being taken up by the US government at the highest level, the US ambassador to India Timothy J Roemer said here on Monday before his meeting with home minister P Chidambaram.

"I just had a very successful meeting with the Home Minister where I talked about working very closely for cooperation with government of India and government of US on counter-terrorism issues," Roemer told reporters after the meeting.

On US granting access to Headley, he said, "This is an issue that is being taken up at the highest levels of the US government day and night constantly."

India has been seeking access to Headley, a Pakistani-origin American, to unravel all details of his activities regarding the 26/11 attacks and plans for further strikes in this country.

The US has shared with India a lot of information based on his interrogation but has so far refused access to him, citing its legal difficulties.

Headley recently entered into a plea bargain with the US government under which he offered to present himself for access through video conferencing, deposition or Letters Rogatory (official request).

"As former commissioner of 9/11 probe, somebody who has experienced loss of life, we lost 3000 people, we empathised here in Mumbai with Indian people the tragic loss of life here and we want to make sure that justice is brought forward to all those involved in that kind of attack," Roemer said.

"It is in both government of India and government of US' interest to work together to protect common people from attacks wherever may they come from," the ambassador said.

Foreign secretary Nirupama Rao yesterday said the Home Ministry and related agencies are in touch with their US counterparts over the access issue and "we are satisfied with the progress these negotiations have made".