Because of uncertainty over visas and an ongoing conflict with the United States, the Iran team is commuting from its tournament base in co-host Mexico for its three group games in the United States.

United States authorities require Iran's players and staff to enter within 24 hours of a match and leave the same day, leading team coach Amir Ghalenoei to say Iran was the "most oppressed" team participating in the tournament.

"The Football Federation of Iran believes these restrictions are inconsistent with the principles of providing equal conditions for participating teams and may affect their technical preparation," An Iran Football Federation statement released this weekend read.

FIFA did not immediately respond to requests for comment.

Andrew Giuliani, director of the White House World Cup Task Force, told British newspaper The Telegraph that he would be open to renegotiating the terms of Iran’s entry to the United States.

He added that Washington could consider allowing Iran to stay longer around its matches.

"Look, everything is dynamic, things can be discussed on this and we certainly want to create competitive fair play on the field, that's why every coach on the team has got their visa, has the opportunity to come in," he said in Seattle ahead of United States' match against Australia, which it won 2-0.

"The president [Donald Trump] wants to make sure this tournament strikes a competitive balance, while also making sure bad actors don’t get into the country. We’ve done that, with a month to go."

Iran coach Ghalenoei said the disruption had affected his team in its 2‑2 draw with New Zealand.

"Under the coaching staff's plan, the national team needed to travel to the host city two days before each match in order to achieve optimal technical and physical condition, and then return to their base the day after the match," the federation said.

"However, for the opening match against New Zealand, this request was not approved."

The US Department of Homeland Security said the measures were safety precautions agreed with Iran, which faces Belgium on 22 June (AEST) in Los Angeles and will conclude its Group G fixtures against Egypt on 28 June (AEST) in Seattle.

"The team will be allowed to come in match day minus one, so the day before the match. They'll be asked to leave the day that the match wraps up, so the evening of the match," a department spokesperson said.

"Again, the president [Trump] wants to make sure that we're talking about what actually happens on the pitch. A lot of that is making sure that things are safe and secure, not just around the stadiums, but around base camps and training sites."