Pakistan has pitched for unconditional resumption of talks, but India has made it clear that meaningful dialogue will not be possible unless Islamabad takes action against the masterminds of the Mumbai mayhem.

The US has also intensified pressure on Pakistan, asking it to bring the perpetrators of the Mumbai attacks, including Saeed, to justice.

US Ambassador to India Timothy J. Roemer Friday called for 'swift punishment' for architects and perpetrators of the Nov 26 Mumbai mayhem.

'Swift and lengthy punishment for six suspects of Mumbai attacks in Pakistan is important for the US and India,' Roemer told reporters in New Delhi.

The ambassador said it was important for the US, India and the world that Pakistan takes action against Saeed, the founder of Lashkar-e-Taiba-turned-Jamaat-ud-Dawa and dismantle the terror infrastructure in that country, a demand India has been making for long but without much response from the Pakistani side.

'Going after Hafiz Saeed and dismantling terror infrastructure in that region is extremely important for both US and India,' the envoy said.

'It is extremely important that these perpetrators be brought to justice and put behind bars, and receive sentences commensurate with their crimes against India, US and the world,' he said.

The US envoy had made the same point in Mumbai Thursday when he described the Pakistan-based LeT as a 'regional and global' threat for the US and India.