Arun Kumar/IANS

Washington, Apr 12: Hours after Prime Minister Manmohan Singh expressed concern over Pakistan's will to punish those responsible for the terrorist attacks in Mumbai, President Barack Obama asked Islamabad to move against the perpeterators.

A couple of hours after meeting Manmohan Singh, Obama Sunday told Pakistani Prime Minister Yusuf Raza Gilani that the Indian leader was sincere in improving ties with Islamabad, but wants Pakistan to take action against those responsible for the Mumbai attacks.

Obama, according to diplomatic sources, told Gilani at their 40-minute meeting that he also personally believes that Pakistan taking action against those responsible for the Mumbai terrorist attack "would be a positive thing".

The US president also made no commitment on the issue of an India-type civil nuclear deal to meet Pakistan's acute energy needs saying there is need to have a proper balance between progress and security concerns.

Voicing his desire for an improved India-Pakistan relationship, Obama said he believes that this would be not only beneficial to the South Asian neighbours, but would also have a positive impact on the overall situation in the region.

"Obama began by noting that he is very fond of Pakistan, having visited the country during college," the White House said in a statement later.

"The President discussed with the Prime Minister (Gilani) the bilateral progress made during the March 24-25 Strategic Dialogue and reiterated the US pledge to work with Pakistan to address issues of mutual concern in the long-term relationship," it said.

"The Prime Minister (Gilani) also indicated his approval of the progress made during the Strategic Dialogue and his hope that the working groups that have been established to address various aspects of the relationship would yield progress in advance of the next Strategic Dialogue meeting, scheduled for late 2010 in Islamabad," it said.

According to the White House, Gilani indicated his assurance that Pakistan takes nuclear security seriously and has appropriate safeguards in place.

The Pakistani officials later said that the US president told them that he is satisfied with the measures taken by Islamabad for the safety and security of its nuclear weapons.

Gilani not only sought an India type nuclear deal saying it was fully qualified, but also lobbied hard for international acceptance as a responsible nuclear state soon after his arrival.

"The prime minister is arguing for Pakistan's acceptance as a responsible nuclear state at every opportunity he gets, from his meeting with Mr Obama to his speech at the summit," a Pakistani official said.