Nigeria's national security adviser has urged the electoral commission to delay next month's elections to allow more time for voter card distribution.

Sambo Dasuki, speaking in London, said 30 million cards had been distributed over the last year but the same number still remained to be handed out.

The elections, scheduled for 14 February, are the first in Nigeria to require voters to have biometric cards.

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.