WASHINGTON: US President Barack Obama on Wednesday said Washington "can make sure that Pakistan's nuclear arsenal is secure," even as heexpressed grave concern over the deteriorating situation in the militancy-stricken country.

At a White House press conference to mark his first 100 days in office, Obama expressed confidence about US control over Pakistan's nuclear weapons, perhaps through military-to-military cooperation, in the face of extremist advances in the country. In the process, he also hinted that Washington had contingency plans to handle the situation if it went out of Islamabad's hands.

Asked if he could reassure the American people that, if necessary, America could secure Pakistan's nuclear arsenal and keep it from getting into the Taliban's hands, Obama replied: "I'm confident that we can make sure that Pakistan's nuclear arsenal is secure, primarily, initially, because the Pakistani army, I think, recognizes the hazards of those weapons falling into the wrong hands."

The carefully calibrated reply referring to primary security appeared to suggest the US has secondary back-up plans in the event of any exigencies, something the intelligence analysts' community has long considered inevitable.

When the reporter followed up to seek a more precise answer, asking if in the worst case scenario, the US military could secure the nuclear weapons, Obama responded crisply: "I'm not going to engage in hypotheticals of that sort. I feel confident that that nuclear arsenal will remain out of militant hands. Okay?"

The exchange was punctuated by a suo motu expression of concern about the situation in Pakistan by the US President, not because it was about to be overrun by Taliban, he said, but because the civilian government was very fragile and was not delivering basic services and governance, which was providing space for extremists.

It was a surprisingly blunt vote of no-confidence in a civilian government whose leader is about to embark on a visit to Washington next week. There has been speculation in some quarters that Washington is not averse to another military takeover if the civilian government does not assert itself over the extremists.

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Obama also referred to what has now become a mantra for his administration: Pakistan should stop worrying about the non-existent military threat from India and tackle its own home-grown extremism.

"On the military side, you're starting to see some recognition just in the last few days that the obsession with India as the mortal threat to Pakistan has been misguided, and that their biggest threat right now comes internally," Obama said, adding, "we want to continue to encourage Pakistan to move in that direction, and we will provide them all the cooperation that we can."

The President seemed to be referring to the reported movement of some 6000 Pakistani troops from the border with India to its western areas recently, even as he made the case for a large civilian and military aid package for Pakistan that Congress is going to take up in the next few days, ahead of the visit to Washington DC next weekend by President Asif Ali Zardari. The 6000 troops were moved to the Indian border in the aftermath of the Mumbai massacre, so essentially the Pakistan military has returned to the pre-Mumbai configuration.

There is strong pressure on Pakistan from Washington to deploy regular troops rather than its constabulary or para-military in the battles against extremists, but Islamabad is said to be desisting, holding out for greater military aid and equipment to carry out the task.

There is considerable tension between the two sides on this issue, and a perceptible lack of trust in Washington about Pakistan's claims that it is routing the extremists and re-established control in the territories it has lost to them. The suggestion here is that Pakistan is shadow boxing to ensure the U.S aid package gets through and its military is yet to get rid of its India fixation.