The Pakistani President, Pervez Musharraf, says his country is safe as long as the military stays in charge.
President Musharraf has appointed Mohammadmian Soomro as PM
Gen Musharraf told the BBC that if the elections were held under disturbed conditions, Pakistan's nuclear weapons could fall into the wrong hands.
A senior US envoy, John Negroponte, has met Gen Musharraf in Pakistan to discuss the deepening political crisis.
Diplomats said he had delivered a very strong message calling for an end to the state of emergency.
Mr Negroponte, the US Deputy Secretary of State, was also expected to try to revive a deal between opposition leader Benazir Bhutto and Gen Musharraf.
He arrived in Pakistan on Friday and spoke on the telephone to Ms Bhutto, telling her "moderate forces" should work together to get Pakistan back to democracy.
He is expected to call for the release of thousands of lawyers and political prisoners and an end of emergency rule as a pre-requisite for a fair election.
Mr Negroponte also met General Ashfaq Kiyani, Pakistan's deputy army chief of staff and Gen Musharraf's chosen successor if he resigns as head of the army as promised.
A military official told AFP news agency they had "discussed matters of mutual interest and security".
But Gen Musharraf has defended his decision to impose emergency rule on Pakistan.
Some opposition supporters did not welcome Mr Negroponte's visit
In an interview with BBC Radio 4's Today programme he said that if elections were held in the wrong environment, the results could lead to chaos.
And if that happened, he argued, Pakistan's nuclear weapons could become vulnerable.
"They cannot fall into the wrong hands, if we manage ourselves politically. The military is there - as long as the military is there, nothing happens to the strategic assets, we are in charge and nobody does anything with them," he said.
Gen Musharraf told the BBC it was judges and opposition politicians - not himself - who were trying to derail the political and democratic process in Pakistan.
He demanded an explanation for his portrayal in the Western media in recent months.
"Did I go mad? Or suddenly, my personality changed? Am I Dr Jekyll and Mr Hyde?" he asked.
"Have I done anything constitutionally illegal? Yes, I did it on 3 November," he said, referring to his imposition of emergency rule. "But did I do it before? Not once."
"Who is trying to derail the political and democratic process? Am I? Or is it some elements in the Supreme Court - the chief justice and his coterie... and now some elements in the political field?"
Meanwhile two leading independent television channels in Pakistan have been forced to shut down completely.
Cable broadcasts of the stations, Geo and ARY, were stopped when Gen Musharraf imposed emergency rule two weeks ago. But the two channels had been able to broadcast on satellite out of Dubai.
Now the authorities in Dubai have ordered them to stop satellite transmissions.
Angry journalists held a march through the Pakistani city of Karachi, to protest at what they say was direct pressure from Gen Musharraf to shut down the two channels.
Benazir Bhutto was placed under house arrest on Tuesday
'Corrupt and unpopular'
Gen Musharraf has criticised former Prime Minister Bhutto, despite recent efforts by the two to form an alliance.
He said Ms Bhutto feared the polls, set for January, because she was corrupt and unpopular.
Gen Musharraf said she was "the darling of the West" but that "she would not like to go into an election because her party is not in a state to win at all".
"Therefore, I will certainly go for the election, in spite of any agitation by her. We will not allow her that," he said.
Ms Bhutto, who was released from house arrest on Friday, has said that she will meet other opposition leaders to discuss a boycott of January's assembly elections.
The opposition says polls under emergency rule would lack credibility.
Washington had been hoping for Ms Bhutto and Gen Musharraf to work together to give his government more support in its fight against pro-Taleban extremists.
But Ms Bhutto again appeared to rule this out.
"I can't see how I can team up with somebody who raises hopes and dashes them... He talked to me about a roadmap to democracy and imposed martial law," she said.
The US administration has made repeated calls for the emergency to be lifted and for Gen Musharraf to return the country to civilian rule.
Gen Musharraf says he will resign as head of the army once the Supreme Court has ratified his next term as president.