Football’s world governing body does not recognise the election of Giwa on 26 August.
“I remain the president of the NFF, a legitimate congress elected me and that is how it is,” Giwa told BBC Sport.
“What I have said [at a public hearing] is that anyone that is aggrieved has the right to appeal to the NFF appeal committee.
“If an appeal committee or the Court of Arbitration for Sport sits today and quash my election, I will humbly vacate office.”
Should Giwa refuse to leave and the ban comes into force on Monday it means the African champions would not be able to play their Africa Cup of Nations qualifier on 10 September in South Africa.
The Confederation of African Football says if the Super Eagles miss that match they would be disqualified from the qualifying campaign.
The ban will only be lifted when the NFF board as it stood on 25 August, with Aminu Maigari as president, are allowed back to their offices to work.
Maigari’s board met in the Nigerian capital Abuja on Thursday to adopt a new roadmap leading to the NFF elections as directed by FIFA.
Nigeria were banned from global football for nine days in July for government interference in the running of the football federation when Maigari was forced out of his post by a court ruling.
After his reinstatement, he was voted out of office by the NFF’s executive committee a few days later. However, FIFA did not accept this and Maigari was once again back as president in August.
Nigeria’s Sport Minister, Tammy Danagogo, may have withdrawn his support for the defiant chairman of Giwa FC of Jos.
Speaking earlier in the week through his Media Assistant, Patrick Omorodion, Danagogo said the nation must come first ahead of any individual.
“If they (FIFA) say the way out is for another election to be held, we would ensure that it is done for peace to return to our football,” Omorodion said on behalf of his boss.
The minister further urged FIFA not to ban the country over the internal wrangling rocking the NFF, insisting that FIFA should rather slam the individuals bringing the game to disrepute by their actions.
“It is also not fair for FIFA to ban a country over the actions of individuals. If they feel that an individual has gone against their statutes, such individual should be singled out and sanctioned and not the entire country,” Danagogo pointed out.
He stressed that he was also aware that FIFA or football federations ban some of their members for offences against the football statutes and expects that the same thing should apply in the present case of the NFF.