Asked by an AFP reporter aboard Air Force One if he was considering US troops on the ground in Nigeria or air strikes, Trump replied: "Could be, I mean, a lot of things -- I envisage a lot of things."

"They're killing the Christians and killing them in very large numbers. We're not going to allow that to happen," he added.

In an explosive post on his Truth Social platform on Saturday, Trump said that he asked the Pentagon to map out a possible plan of attack in Nigeria, one day after warning that Christianity was "facing an existential threat" in Africa's most populous country.

Nigeria, which is almost evenly divided between a Muslim-majority north and a largely Christian south, is embroiled in numerous conflicts that experts say have killed both Christians and Muslims without distinction.

In his post, Trump said that if Nigeria does not stem the killings, the United States will attack and "it will be fast, vicious, and sweet, just like the terrorist thugs attack our CHERISHED Christians."

Nigerian President Bola Ahmed Tinubu's spokesman Daniel Bwala told AFP on Sunday that "Nigeria is US's partner in the global fight against terrorism. When leaders meet there would be better outcomes."

"Nigeria welcomes US support to fight terrorism as long as it respects our territorial integrity," he said.

"We do not see the (Trump's social media post) in the literal sense," he said.

"We know that Donald Trump has his own style of communication," he said, suggesting the post was a way to "force a sit-down between the two leaders so they can iron out a common front to fight their insecurity."

Earlier Bwala had suggested in a post on X that the two leaders could meet soon.

"As for the differences as to whether terrorists in Nigeria target only Christians or in fact all faiths and no faiths, the differences if they exist, would be discussed and resolved by the two leaders when they meet in the coming days, either in State House or White House."

Bwala, who was speaking on the phone from Washington, declined to disclose details of any potential meeting.

Trump posted on Friday, without evidence, that "thousands of Christians are being killed (and) Radical Islamists are responsible for this mass slaughter."

Nigeria has denied that Christians have been targeted by jihadist attacks more than other faiths.

"The characterisation of Nigeria as religiously intolerant does not reflect our national reality," Tinubu said on social media Saturday.