Iran's football chief says their World Cup host "is FIFA, not Mr Trump or America" and has called for respect towards the Islamic Revolutionary Guard Corps (IRGC) if the national team is to travel to the United States for this summer's tournament.

There remains uncertainty over Iran's participation in the World Cup because of the war with the US and Israel.

Iranian FA (FFIRI) chief Mehdi Taj was among a delegation that turned back at the Canadian border before last week's Fifa Congress in Vancouver because of what they felt was disrespectful treatment by immigration officials.

Taj said the decision to return home was their own choice, but Canada's immigration minister confirmed to parliament that the FFIRI president's visa had been cancelled while he was in the air because of his links to the IRGC.

The IRGC was set up to defend Iran's Islamic system and has become a major military, political and economic force in the country. However, the group is listed as a terrorist organisation in Canada and the US.

FIFA secretary general Mattias Grafstrom wrote to express regret for the "inconvenience and disappointment" and has invited FFIRI to Zurich for a meeting about their World Cup preparations on 20 May.

Taj, who served as a high-ranking IRGC official, told state broadcaster the Islamic Republic of Iran Broadcasting (IRIB) on Tuesday that he would seek assurances from the governing body about the treatment of Iranian officials at the World Cup.

"We need a guarantee there, for our trip, that they have no right to insult the symbols of our system - especially the IRGC," Taj said.

"This is something they must pay serious attention to. If there is such a guarantee and the responsibility is clearly assumed, then an incident like what happened in Canada will not happen again."

The US, Canada and Mexico will co-host the World Cup between 11 June and 19 July.

Iran are scheduled to play two games in Los Angeles, against New Zealand on 15 June and Belgium on 21 June, and then Egypt in Seattle on 26 June.

U.S. Secretary of State Marco Rubio said last week that no one with ties to the IRGC would be admitted to the country.

"We are going to the World Cup, for which we qualified, and our host is Fifa - not Mr Trump or America," Taj said.

"If they accept hosting us, then they must also accept that they must not insult our military institutions in any way.

"Because if they do, then naturally it could create the same kind of situation that happened in Canada, where there was a possibility we might have to return.

"So there must be this kind of guarantee so that we can go with peace of mind."

The US and Israel launched air strikes on Iran in February.

Iran was the only FIFA federation among the 211 member countries that did not have representation at the FIFA congress in Vancouver.

FIFA president Gianni Infantino said Iran will be going to the US and playing as scheduled, despite Iran's request in March to move its matches to Mexico.