Nigeria's national security adviser has urged the electoral commission to delay next month's elections to allow more time for voter card distribution.
The polls are the first in Nigeria to require voters to have biometric cards.
Nigeria, wracked by a violent uprising by Islamists Boko Haram, is scheduled to hold the election on 14 February.
The security chief, Sambo Dasuki, also said that neighbouring Chad was sending troops to help fight the militants, who control many towns and villages.
And he criticised "cowards" within Nigeria's armed forces for hampering the campaign against the insurgents.
"We have people who use every excuse in this world not to fight," he told an audience at the Chatham House think-tank in London, adding "there is no high-level conspiracy within the army not to end the insurgency".
Several soldiers have complained about not being given the weapons they need to fight Boko Haram.
Boko Haram at a glance
- Founded in 2002, initially focused on opposing Western education - Boko Haram means "Western education is forbidden" in the Hausa language
- Launched military operations in 2009 to create Islamic state
- Thousands killed, mostly in north-eastern Nigeria - also attacked police and UN headquarters in capital, Abuja
- Abducted hundreds, including at least 200 schoolgirls
- Controls several north-eastern towns
- Launched attacks on Cameroon
Speaking about the forthcoming election, Mr Dasuki said 30 million cards had been distributed over the last year but the same number still remained to be handed out.
The measure was introduced to guard against electoral fraud.
President Goodluck Jonathan is standing for re-election. His main challenger is former military ruler Muhammadu Buhari.
Mr Dasuki, speaking at the London think-tank Chatham House, said he had told the chairman of the Independent National Electoral Commission (Inec) that it would be sensible to postpone the poll within the three months it had to legally take place.
"It costs you nothing, it's still within the law," Mr Dasuki said he had told the Inec chairman.
He told Chatham House that a postponement would be "safer for all of us".
"If in one year you've distributed 30 million, I don't see how you will distribute another 30 million in two weeks. It doesn't make sense."
But Inec spokesman Kayode Idowu said there were currently no plans to delay, according to Reuters news agency.
"It is not a conversation of the commission's at all. As far as we are talking now, the date is what it is," Mr Idowu said.
Lai Mohammed, spokesman of the opposition All Progressives Congress (APC), told Reuters he was not happy with the proposal.
"Why are they not ready? Why should we postpone? We say 'no' to postponement," he said.
The elections look to be the closest fought since the end of military rule in 1999.
They pit President Jonathan of the governing People's Democratic Party (PDP) against Mr Buhari, who ruled Nigeria from January 1984 until August 1985 following a coup.
Nigeria is gripped by a violent uprising in the north-east led by Islamist Boko Haram rebels.
But Mr Dasuki stressed that adequate security will be in place for the poll and that those displaced by the fighting will be able to vote.