Washington, Dec 31: US House of Representatives Speaker Nancy Pelosi has said that Washington should address "troubling questions" about Pakistan’s probe of Benazir Bhutto’s assassination and its cooperation in war on terror before extending any more aid.

She called for an international investigation into the December 27 assassination of Bhutto, adding that US law made assistance to Pakistan conditional on Islamabad’s cooperation in the war against terrorism.

Pelosi said unless the Bush Administration confirmed that Pakistan was cooperating, it should halt all further aid to the country.

Meanwhile, the Bush Administration urged Pakistan to move ahead with free elections but declined to push Islamabad to hold the elections as scheduled.

White House spokesman Scott Stanzel said in a statement that the US wanted Pakistan to "continue on the path to democracy by holding free and fair elections".

"The timing of those elections will be up to the Pakistanis, " the Daily Times quoted Stanzel, as saying.

However, the US State Department said that Pakistan would also announce a new date for the polls if elections were delayed. (ANI)