'We feel that concerted action has to be taken by Pakistan. The evidence given by India against Saeed is sufficient and valid in any court of law,' the official said.

'We have been sharing evidence. This evidence has been shared in a painstaking and professional manner. But no action has been taken,' the official said while underlining India's mounting frustration at Pakistan's attitude.

'Pakistan should take this evidence, study it seriously with utmost care and take leads forward. This is necessary to complete the investigation and to ensure that justice is done,' the official said.

'The terror from across the border is an issue of tremendous concern and of continuing concern for India,' he said.

After the Sharm-el-Sheikh contentious formulation on delinking terror from the dialogue process created a massive political furore in India, the government has toughened its posture and reverted to the old line about no meaningful talks unless Islamabad takes action against the Mumbai terrorists.

A week ago, External Affairs Minister S.M. Krishna underlined India's increasing exasperation with Pakistan's vacillation and asked it to take 'effective steps' to dismantle the infrastructure of terrorism. He stressed that a meaningful dialogue will only be possible after Pakistan fulfills its commitment not to allow its territory to be used for terrorist activities against India and bring the perpetrators of the Mumbai attacks to justice.