WASHINGTON-Pakistans military has pushed Taliban extremists back from territory they had gained, an Obama administration official said, adding, that the US must continue providing non-military aid to preserve those gains. 'It is vital that we help address the economic and social conditions that extremists exploit in western Pakistan with more economic aid, Paul Jones, US deputy special representative for Afghanistan and Pakistan, told a Senate panel. Such aid would help ensure that terrorists dont return 'to fill the vacuum once military operations have ended, Jones told a Sub-Committee of the Senate panel on homeland security in Washington. Pak military operations that began two months ago in the countrys northwest 'have successfully rolled back Taliban gains, but they underscored that there are no quick fixes when combating a ruthless insurgency, Jones said. The Taliban had moved within 100 miles of the capital of Islamabad, to the Swat valley and nearby districts. He said the US and the international community need to aid 2.3 million Pakistanis displaced by the fighting and help build the govts civilian capacity in remote regions that have been infiltrated by extremists, said Jones, the deputy to US envoy Richard Holbrooke. Some in Pakistan distrust the US, believing it will abandon their country once its counter-terrorism goals are achieved, Jones added. If the US doesnt help address poverty and govt weaknesses or enhance trade and investment in Pakistan, the Taliban will regain the upper hand, he added. The US is providing more than $164 million to refugees in Pakistan and helping raise more than $300 million from other countries, he said. The US is also sending American doctors of Pakistani origin, including five women, to work in temporary camps, Jones said. Senator Tom Carper, a Delaware Democrat and chairman of the panel, said US officials are concerned about Pakistans nuclear weapons,including the potential for militants to insert sympathizers into laboratories or fuel-production facilities or to seize a weapon in transport. 'Preventing Pakistans nuclear weapons and technology from falling into the wrong hands should be a top priority for both our countries, Carper told Jones. The Senate recently unanimously passed legislation that, if approved by the House, would authorize $1.5 billion annually in non-military assistance to Pakistan for five years.