According to Monguno, the armed forces and intelligence agencies are working to keep Nigerians safe.
The Nigerian Government has again slammed the United States government for issuing a terror alert in Nigeria, which he said created unnecessary fear and apprehension among Nigerians.
SaharaReporters had reported that US Embassy in Nigeria issued a terror alert to its citizens to leave Abuja, Nigeria's capital territory and that those planning to visit Abuja should shelve their trip till further notice.
The Embassy did not provide the details of the terrorist threat but Nigeria has been on high alert since last Sunday following which several other Western nations raised their travel alerts.
Nigerian security forces are battling jihadist fighters mostly in the northeast of the country, but the terrorists have claimed several recent attacks near the capital.
The US also warned of the risk of a terror attack in South Africa, leading authorities there to insist that a series of weekend events were properly protected.
President Muhammadu Buhari on Monday met with security chiefs in Abuja to further review and strengthen the security network in the country.
The President, who was initially scheduled to inaugurate the new Technology and Innovation Complex of the National Agency for Science and Engineering Infrastructure (NASENI), received briefs from the security chiefs on areas that need more attention.
Briefing journalists shortly after the emergency meeting at the State House, the National Security Adviser (NSA), Maj. Gen. Babagana Monguno (retd.), described the terror alert issued by the US as needless.
He urged Nigerians to go about their businesses without any fear.
According to Monguno, the armed forces and intelligence agencies are working to keep Nigerians safe.
Monguno addressed journalists alongside the Minister of Foreign Affairs, Geoffrey Onyema, the Chief of Defence Staff (CDS), General Lucky Irabor, and the Director-General of the National Intelligence Agency (NIA), Ahmed Rufai Abubakar.
Attendees of the emergency National Security Council meeting included Vice President Yemi Osinbajo; Secretary to the Government of the Federation (SGF), Mr Boss Mustapha; and the Chief of Staff to the President, Professor Ibrahim Gambari.
Others were the Minister of Defense, Major General Bashir Magashi (Rtd); Minister of Interior, Rauf Aregbesola; the Attorney-General and Minister of Justice, Abubakar Malami; and Minister of Police Affairs, Mohammed Maigari Dingyadi.
The Chief of Defence Staff, General Lucky Irabor, led the service chiefs, including the Chief of Army Staff, Lieutenant General Farouk Yahaya; Chief of Naval Staff, Vice Admiral Awwal Gambo; Chief of Air Staff, Air Marshal Isiaka Oladayo Amao to the meeting. The Chief of Defence Intelligence, Major-General Samuel Adebayo, was also in attendance.
SaharaReporters had also reported that President Buhari through his Special Assistant on Media and Publicity Garba Shehu, assured Nigerians that there was no cause for alarm and that Nigerians should be calm while observing strict vigilance.