US President Donald Trump has warned that he could order more airstrikes on Nigeria if Christians continue to be killed in the West African nation.

In a wide-ranging interview with the New York Times, Trump was asked whether the Christmas Day strikes in Nigeria's northern Sokoto state, targeting Islamist militants, were part of a broader military campaign.

"I'd love to make it a one-time strike. But if they continue to kill Christians it will be a many-time strike," he said.

Nigeria's government has rejected Trump's earlier accusations that it is failing to protect Christians from jihadist attacks, saying that "Muslims, Christians and those of no faith alike" are targeted.

Claims of a genocide against Nigeria's Christians began circulating last year in some right-wing US circles - but organisations monitoring political violence in Nigeria say most victims of the jihadist groups are Muslims.

When questioned about this in the interview published on Thursday, Trump replied: "I think that Muslims are being killed also in Nigeria. But it's mostly Christians."

A spokesperson for Nigeria's foreign minister did not directly comment on the possibility of more air strikes but told the BBC: "We will continue to engage constructively and work with partners, including the United States, on the basis of mutual respect, international law, and Nigeria's sovereignty.

''Nigeria remains committed to protecting all citizens, Christians and Muslims alike, without discrimination,'' said Alkasim Abdulkadir.

Nigeria's population of more than 230 million people is roughly evenly divided among Christians, who predominate in the south, and Muslims, who are mostly in the north.

For the past 15 years, the north-east of the country has suffered from a devastating Islamist insurgency at the hands of jihadist groups such as Boko Haram and those affiliated with the Islamic State (IS) group, based in Borno state.

The country also faces an array of other complex security issues in different regions, including criminal kidnapping gangs, clashes over land and separatist unrest.

The US's Christmas Day strikes hit two camps run by a jihadist group called Lakurawa in the largely Muslim state of Sokoto, in north-western Nigeria near the border with Niger. It is still unclear if there were any casualties as neither the US nor Nigerian government has provided figures - and there has been no update on the outcome of the attack.

Lakurawa established a foothold in the border region a few years ago and hails from areas north of Nigeria in the Sahel.

The US and Nigerian government said after last month's airstrikes that the militants were linked to IS groups in the Sahel - although IS has not linked itself to any of the group's activities or announced ties to Lakurawa as it has done with other groups in the region that it backs.

In the wake of the strikes, Nigeria's Foreign Minister Yusuf Maitama Tuggar told the BBC that it had been a "joint operation" and "nothing to do with a particular religion".

Referring to the timing of the strikes, he said they did not have "anything to do with Christmas" - though Trump said he had ordered them as a "Christmas present".

The foreign minister added that the strikes had had the explicit approval of Nigeria's President Bola Tinubu and the involvement of the country's armed forces.