Nnamdi Azikiwe International Airport in Abuja closes completely for runway repairs on March 8.
Nnamdi Azikiwe International Airport in Abuja closes completely for runway repairs on March 8. Domestic and international flights will be diverted to Kaduna, 170 kilometres (105 miles) away.
Nigeria's aviation ministry has said the planned six weeks of resurfacing work were needed because the runway, which was built in 1982 with a 20-year lifespan, was "dilapidated" and "unsafe".
There have been several reports that potholes have damaged aircraft, prompting one international carrier to cancel its flights on the route.
But Lufthansa, Air France and South African Airways have all said they will not re-route their flights to Abuja from Frankfurt, Paris and Johannesburg, to Kaduna or elsewhere in Nigeria.
British Airways and Turkish Airlines have not made a decision but look likely to follow suit, as both have suspended ticket sales for Abuja flights during the closure.
Malte Liewerscheidt, senior Africa analyst with the Verisk Maplecroft global risk consultancy, said the closure of the capital's airport was "highly symbolic".
Nigeria -- Africa's most populous nation -- is in recession and desperate to turn around sky-high inflation and a weak currency that have deterred overseas investors.
"You have a government that doesn't even keep the airport to its capital open. What does that say?" he told AFP.
"This raises a whole lot of questions for investors about the assets of the Nigerian government."
Kaduna airport manager Amina Ozi Salami maintained the runway was "100 percent better" than in Abuja. But the state of the runway was not the issue, according to analysts.
Gillian Parker, Nigeria analyst at the Control Risks consultancy, said the refusal to re-route showed that major international airlines do not see Kaduna as a "credible alternative".
Salami said work on the terminal building, which was abandoned in May 2015, had restarted and would be completed -- if the contractor was paid -- by early next month.
At the same time, more space was being prepared for storing aviation fuel while the state government was working to improve street lighting on the airport road from the city, she added.
Round-the-clock security has been promised, as well as bus shuttle services to the railway station, from where trains run to the capital twice a day.
"Staff at Abuja airport will be deployed to Kaduna, so all hands are on deck to deliver on services," said Salami, accusing those against the plan of "playing politics".
Questions remain about whether Kaduna will cope with the increase in domestic flights onto which long-haul passengers will have to transfer after arriving in Lagos and Port Harcourt in the south.
"Cancellations and delays associated with domestic airlines, currently starved of funds, are unlikely to abate during this period," said Control Risks' Parker.
"Kaduna airport, in its current state, is poorly equipped and operates without automated services and is likely to struggle with additional traffic."
No figures are available about how much money Abuja stands to lose by having its airport out of action for at least six weeks.
But the president of the Abuja Chamber of Commerce and Industry, Tony Ejinkeonye, said everyone associated with the facility would be "highly affected".
Airlines are the only viable option for relatively speedy travel around Nigeria, as road infrastructure is lacking and security questionable.
Motorists on the Abuja to Kaduna road have been the target of kidnappers while Kaduna state has seen a spate of violent ethnic and sectarian clashes in recent months.
Some travellers could be deterred even with the government's pledge of extra security on the road. More security checkpoints will add more time onto journeys.
One car hire operator in Abuja said travel to Kaduna costs between 25,000 and 30,000 naira ($79-95, 74-89 euros) for a four-wheel drive, and 20,000 to 25,000 naira for an ordinary car.
But prices will likely rise during the closure, the operator added. The Nigerian Railway Corporation has already increased fares on its Kaduna-Abuja route by 25 percent.
Passengers now pay 1,050 naira for a standard ticket and 1,500 for an executive seat, leading to charges of profiteering.