The media reports indicate Pakistan is producing more bomb grade uranium for new generation of nuclear weapons.

These reports have raised questions over the US decision to provide billions of dollars of military aid to Islamabad.

The fears of these funds being misued has gained ground following a confidential briefing by a top military commander.

The briefing done to some US congressmen reveals that Pakistan is rapidly adding to its nuclear weaponry.

This has raised fears about the proposed money being diverted for Pakistan's nuclear programme.

Washington is concerned because the news comes at a time when the US is increasingly focused on trying to ensure that the Taliban does not lay its hands on Pakistan's nuclear arsenal.

The US also feels that Islamabad's move to multiply its nuclear weapons is ill-timed as it comes amid efforts by Obama to bar nations from producing more fissile material.

President Barack Obama has made it clear that the US will consider "all options" to prevent terrorists from seizing Pakistan's nuclear weapons.

But the US has been encouraged by the "decided shift" in Pakistan Army's recognition that the "threat" from Taliban was "much more immediate and serious" than from India.