Iran were the only country not represented as FIFA met on Thursday for its annual congress in Canada.

But Gianni Infantino, president of world football's governing body, reiterated again that the country "will be participating" in this summer's World Cup, to be held in the United States, Canada and Mexico.

There has been uncertainty over Iran's participation in the tournament because of the war with the US and Israel.

But Infantino added, "Of course, Iran will play in the United States of America. The reason for that is simple, because we have to unite. We have to bring people together."

Iranian football federation officials, including its president, Mehdi Taj, were due to attend the Fifa congress in Vancouver, but Iran was the only of 211 nations not present.

The Iranian news agency Tasnim had earlier reported the delegation turned back at the border control, citing their treatment by Canadian immigration authorities.

Canada's foreign affairs minister, Anita Anand, said her understanding is that there was a "revocation" of the permission to enter the country.

Taj is said to have ties to the Islamic Revolutionary Guard Corps (IRGC), which is designated as a terrorist organisation in Canada.

Mark Carney, the Canadian prime minister, said IRGC members are "prohibited from coming" when asked about the issue earlier on Thursday.

Speaking to reporters, he said he was unable to comment on the specifics of individual cases under the country's privacy laws, but noted the IRGC has been listed as a terrorist organisation in Canada for several years.

"There are multiple hurdles in order to get into the country, and I think the important thing is that those hurdles are effective," added Carney.

The Iranian football federation has not yet commented on its absence.

Foreign affairs minister Anand added: "My understanding is that there is a revocation of the permission. It was unintentional, but I'll leave it to the minister to indicate.

"I'll say that on our position on Iran, it is clear from a diplomatic standpoint, we have no diplomatic relationships with Iran. We have not had diplomatic relationships with Iran for over 10 years."

The World Cup begins on 11 June with Iran due to face New Zealand and Belgium in Los Angeles on 15 and 21 June respectively, and then Egypt in Seattle on 26 June.

US President Donald Trump has previously said Iran would be welcome at the World Cup, but added they should not be involved "for their own life and safety".

He was asked about Iran's participation again following Infantino's comments on Thursday and said: "Well, if Gianni said it, I'm OK. I think let 'em play."

Iran had petitioned to have their games played in Mexico, but Infantino has always maintained that the country would take part in the tournament as scheduled.

Infantino aiming to stay on until 2031

Infantino also told Congress that he plans to run for the presidency again when his term finishes next year.

"As you've heard, the electoral period for the presidential election at FIFA starts today," he said.

"I'm honoured and humbled at the same time, and I want to tell you first, the 211 member associations, I want to confirm to you that I will be a candidate for the election of FIFA president next year."

He already has the backing of the South American, Asian and African confederations.

A FIFA president is allowed to complete a maximum of three terms. However, the first three and a half years of Infantino's leadership do not count because he took over following Sepp Blatter's resignation in 2016.

He is therefore eligible to hold the role for four more years, should he win the election in 2027