The US has emphasised that Pakistan has still "lot to do" in combating the menace of terrorism and the immediate focus should be on groups responsible for the ghastly Mumbai terror attacks [Images].

There is a need to "eliminate" such groups, Richard Boucher, the US Assistant Secretary of State for South and Central Asian Affairs, has said in significant comments, which come in the wake of Pakistani authorities trying to blur the focus away from cracking down on the groups like Lashkar-e-Toiba suspected to have masterminded the Mumbai attacks."Pakistan has taken some promising steps, but there is a lot to be done to tackle the menace," Boucher told All India Radio.

The top US official said Washington and New Delhi [Images] were in the process of putting in place "a new kind of cooperation" to prevent such terror attacks in the future. "We are having a very active diplomatic and investigative dialogue with India," he stressed.

Boucher also said that America is seriously following up on the Mumbai attacks, even as India puts in place, better mechanisms and structures, to strengthen internal security. He said the US will also continue to work with Pakistan thoroughly to eradicate the menace of terrorism from their soil.

Earlier this week, Admiral Mike Mullen [Images], Chairman of the US Joint Chiefs of Staff, is believed to have stressed on the the need for Pakistan to do more to address India's concerns, including action against elements linked to the Mumbai attacks, during his meetings with top Pakistani military leadership in Islamabad [Images].

According to a media report in Islamabad, Mullen was "on a mission to urge Pakistan to arrest elements accused by India of being involved in last month's Mumbai attacks for cooling down the mounting tension between the two countries".

India has blamed Pakistan-based elements, including the banned LeT, for planning and carrying out the Mumbai attacks that killed over 180 people. It has asked Pakistan to crack down on these elements.

Pakistan, which carried out a limited crackdown on LeT and its front organisation Jamaat-ud-Dawah, has been insisting that India has not shared any evidence on the attacks.

The US, on the other hand, is concerned that a further escalation in regional tension could result in Pakistan diverting troops from its border with Afghanistan to the Indian frontier.

This would adversely impact the US-led campaign in Afghanistan and make it easier for Taliban [Images] elements based in Pakistan's tribal belt to conduct cross-border raids.