US President Donald Trump's public demand for US World Cup bid could actually work against US interest.

President Donald Trump called on Nigeria and other African countries Monday to endorse the US-Canada-Mexico joint bid for the World Cup in 2026, tying it to US support for them.

"I hope all African countries and countries throughout the world, that we also will be supporting you, and that they will likewise support us in our bid along with Canada and Mexico for the 2026 World Cup," Trump said in a White House press conference with Nigerian President Muhammadu Buhari.

"We will be watching very closely, and any help they can give us in that bid we would appreciate," he said.

The call comes as world football's governing body FIFA prepares to choose between the US-led joint bid and Morocco's at a vote in Moscow on June 13.

Trump appeared to tie the issue to trade, saying just ahead of his mention of the World Cup that the United States hopes "to be the economic partner of choice for nations across the continent and all around the world."

"You see what's happening with respect to trade and the United States. We are being respected again," he said.

It was the second time in a week that Trump weighed in on the bid, suggesting a quid pro quo for the support of other countries.

"The U.S. has put together a STRONG bid w/ Canada & Mexico for the 2026 World Cup," Trump tweeted on Thursday.

"It would be a shame if countries that we always support were to lobby against the U.S. bid. Why should we be supporting these countries when they don't support us (including at the United Nations)?"

Trump's comments however risk incurring the wrath of FIFA, which has strict guidelines forbidding government intervention in football matters.

With strong infrastructure already in place, the North American joint bid has long been as the clear front-runner for what will be the first 48-team World Cup.

But Morocco has secured support from the influential Confederation of African Football as well as countries in Europe, notably France.

Some analysts say Trump's heavy-handed intervention could tilt support away from North American bid.

Jaimie Fuller, one of the founding members of the New FIFA Now advocacy group, believes Trump may weigh heavily on the North American bid, while cautioning that the vote remains finely balanced.

"I wouldn't be stunned if Morocco won this," Jaimie Fuller, one of the founding members of the New FIFA Now advocacy group, told AFP in an interview last week.

"And I wouldn't be surprised if a lot of that was down to the fact that Trump has waded in."