The European Union says its observers will continue to work across Nigeria ahead of next week’s fiercely contested elections.
The statement follows Kaduna state governor Nasir el-Rufai’s controversial comment that foreigners who intervened in the polls would be put in “body bags”.
There has been widespread condemnation of Mr Rufai’s statement, which was made on a local TV station.
The comments were part of a discussion on the recent suspension of the country’s top judge, a move some have said was politically motivated.
The US, EU and UK all expressed concern over the suspension.
During a TV discussion on the subject on Tuesday, Mr Rufai, a key ally of President Muhammadu Buhari, said that Nigeria would not accept foreign interference in its internal affairs.
He added: “They will go back in body bags because nobody will come to Nigeria and tell us how to run our country.”
Mr Rufai later clarified he was only insisting that Nigeria’s sovereignty be respected.
Mr Buhari is running for a second term. His main challenger is former Vice-President Atiku Abubakar.