The White House on Saturday declined to comment on the possibility that Pakistan will postpone elections in the wake of Benazir Bhutto's assassination.
But amid controversy over what exactly killed the popular Pakistan politician, the White House urged Islamabad to thoroughly investigate her death, while avoiding comment on calls for an international probe.
"The Pakistanis are going to have to make their decision based on the conditions following her death," said presidential spokesman Tony Fratto.
"The elections should be free and fair and parties and candidates should be able to conduct an election in an open way," he said in a telephone call.
"But as for the timing, this will be something that the Pakistani authorities will have to determine."
Pakistan's election commission said on Saturday it would hold an urgent meeting on Monday to decide on whether to postpone the January 8 polls because of turmoil caused by Bhutto's death on Thursday in a suicide bombing at a campaign rally.
At least 38 people have been killed and 53 injured in the violence.
In the hours just after the attack on Bhutto on Thursday the United States urged Islamabad to stick to election plans.
In a telephone call US President George W Bush pressed President Pervez Musharraf "to honour Benazir Bhutto's memory by continuing with the democratic process for which she so bravely gave her life."
And a State Department spokesman said a delay "would be a victory for no one but the extremists responsible for this attack."
But with the announcement by the party of former prime minister Nawaz Sharif that they would boycott the polls, and a similar threat by Bhutto's party, Islamabad has moved to consider a postponement anyway.
Asked about concerns inside Pakistan that Musharraf's government did not fully investigate Bhutto's death, Fratto said the investigations needed to be "thorough."
"The investigation is ongoing. The government of Pakistan has a responsibility to ensure that the investigation is thorough and that the citizens have confidence in the results of the investigation."
Bhutto's Pakistan People's Party alleged a cover-up after the government said she had not been shot as earlier reported but instead died after smashing her head on her car's sunroof after the bomb exploded.
Fratto added the United States has not received any request to help in the investigation following the death of the Pakistani opposition leader.
"We haven't received any request for assistance. If we do, we will certainly consider them," Fratto said.
According to the
New York Times
on Saturday, some in the Bush administration want Musharraf to open the investigation into Bhutto's death to foreign expertise, including from the US Federal Bureau of Investigation.
Meanwhile, Fratto refused to comment on a call from Democratic Party hopeful Hillary Clinton for a international investigation into Bhutto's death.
"The investigation is being handled by the Pakistani authorities," he said.