The agency said criminal groups were increasingly preying on vulnerable Nigerians, particularly young women and girls.
The agency stated that the arrangement would foster intra-African mobility.
Ms Nandap said the attack was carried out by unidentified armed men at about 10:00 p.m. on Thursday.
This incident and other similar ones have weakened the morale of immigration officers.
An X user, @teejayviruz, urged the federal government to instead round off the new fees to a million.
Mr Akinlabi also advised Nigerian students in the U.S. to remain in active study programmes and refrain from unauthorised withdrawal or absenteeism.
The NIS said the e-visas were non-extendable, urging applicants to apply for visas that best match the duration and purpose of their visit.
Mr Akinlabi said that vacancies were advertised through the NIS website, official government channels, and recognised national newspapers.
The NIS comptroller general said the rollout in Europe was the second phase of the rollout of the service for Nigerians in the diaspora.
