Nigeria's military on Tuesday said that a call by the country's top military officer for a swift end to the Boko Haram insurgency had been "taken too literally".

Air Marshal Alex Badeh was appointed chief of defence staff last month and on January 20 said: "The security situation in the northeast must be brought to a complete stop before April 2014."

Since the statement was made, Badeh's home state of Adamawa in northeast Nigeria, has seen a number of suspected Boko Haram attacks, including one on a church on January 26 which killed 26.

An attack on a busy market in neighbouring Borno on the same day killed 52, while last weekend a Muslim cleric who had previously criticised the group was shot dead in the northern city of Zaria.

Defence spokesman Chris Olukolade issued a statement on Tuesday entitled "Terrorism: DHQ (Defence Headquarters) clarifies CDS (chief of defence staff) comment on April deadline".

In it, he acknowledged that Badeh's assertion had generated debate as well as "interpretation and reaction, especially from the media", without denying that the words reported had been said.

But he added: "The remarks by the CDS was meant to motivate commanders and troops to work harder towards restoration of normalcy as envisaged in the states under Emergency rule.

"Unfortunately, the charge has been taken too literally to mean (a) definite promise to end terrorism by April."

Adamawa, Borno and Yobe have been under emergency rule since May last year in a bid to stop the insurgency, which has claimed thousands of lives since 2009.

Parliament approved a six-month extension to the special powers on November 20.

But attacks have continued, many in more remote, rural areas of northeast Nigeria, although militant fighters carried out an early morning raid in the Borno state capital Maiduguri in December.

That attack and a car bomb that ripped through a market in the city in January, killing 19, saw President Goodluck Jonathan replace his top brass on January 16.

Olukolade said that by referring to the end of April, Badeh was "simply being optimistic" about his new senior colleagues' determination to tackle the issue.

It was also a call to restore order to the country to avoid having to seek a further extension to emergency powers in April and getting stuck in a potential parliamentary logjam, he added.

Badeh had said he wanted to avoid having to "go and start begging and lobbying" parliament.

"The CDS statement should not be mistaken for a false sense of hope or mere grandstanding as have been imputed by some individuals," Olukolade added.

"Ending terrorism anywhere has never been and cannot be precisely determined by a directive."