Nigerian Foreign Minister Yusuf Tuggar said on Tuesday that state involvement in religious persecution was "impossible" in Nigeria under the country's laws and constitution.

He was responding to a question about US President Donald Trump's warning of possible "fast" military action in Nigeria if it fails to crack down on the killing of Christians by Islamist insurgents.

Speaking in Berlin alongside his German counterpart Johann Wadephul, Tuggar pointed to his country's "constitutional commitment to religious freedom and rule of law."

"This is what shows that it's impossible for there to be a religious persecution that can be supported in any way, shape or form by the government of Nigeria at any level, be it federal, be it regional, be it local, it's impossible," he said.

Trump announced on Truth Social on Monday that his government would immediately stop all aid and assistance to Nigeria, Africa's most populous nation and top oil producer.

If the United States sends in military forces, it would go in "'guns-a-blazing,' to completely wipe out the Islamic terrorists who are committing these horrible atrocities," Trump wrote.

The Nigerian presidency responded by saying that it would welcome US help in fighting Islamist insurgents as long as the country's territorial integrity is respected.

An adviser to Nigerian President Bola Tinubu told Reuters that Trump's comments were not being taken literally and that the US president actually "thinks well of Nigeria".