The earlier date had been August 29.
Director-General of the NCAA, Musa Shuaibu Nuhu, revealed the news during a Presidential Task Force COVID-19 briefing in Abuja.
He said while airlines and airports were ready to operate, other non-aviation logistics prompted the one-week extension.
“We have other non-aviation logistics we are still working on, mostly the COVID-19 protocol tests and online platform,” he said. “We need to get this ready.”
Mr Nuhu described September 5 as a “sacrosanct date”, noting that “the initial announcement was anytime from the 29th.”
“In due course, we will be announcing the protocols for the resumptions and we will be giving further details,” he said. “Hopefully early next week, we will release this.”
Nigeria started to restrict international flights in March as part of efforts to restrict the spread of the COVID-19 virus.
The shutdown, which included inter-state travel and closure of public places and schools, contributed to the decline of the country’s economic growth.
In July, the country resumed domestic flight operations with international flights scheduled to follow.
The PTF Chairman, Boss Mustapha, during the briefing on Thursday, said he hopes the reopening of international flights will help to re-open the economy.