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Iran’s national soccer team arrived in North America under a cloud of diplomatic tension after U.S. officials denied visas to two senior Iranian Football Federation leaders ahead of this month’s World Cup, drawing sharp protests from Tehran over what it called politically motivated interference in sport.

Every player on Iran’s 30-man squad and all coaching staff members received visas to participate in the tournament, which is being jointly hosted by the United States, Canada and Mexico. However, Iranian Football Federation Secretary General Hedayat Mombeini and Vice President Mehdi Mohammad Nabi were both denied entry. It was unclear whether federation President Mehdi Taj had received a visa.

Compounding the tensions, the Trump administration imposed a condition requiring the Iranian delegation to leave U.S. soil the same day as each of its matches, barring the team from remaining in the country overnight.

Citing safety concerns, Iran’s players and coaches agreed to base their operations in Tijuana, Mexico, rather than on U.S. soil. The squad had been training in Turkey before flying directly to Mexico on Saturday.

U.S. Ambassador to Turkey Tom Barrack posted on social media Friday praising the U.S. Embassy in Ankara for processing the team’s visas, calling the World Cup an opportunity to “welcome competitors and fans from around the world.” The post drew swift pushback from the Iranian embassy in Turkey, which accused the U.S. of “deliberate and discriminatory treatment” and said the ambassador’s remarks amounted to attempting to “whitewash conduct that violates FIFA regulations.”

The Iranian Football Federation said it would file a grievance with FIFA, calling the visa conditions an example of the U.S.’s continued “vindictive behavior” toward the squad. The federation said American officials had denied Iran “the opportunity for a level playing field and a competition free from discrimination.”

A FIFA complaint may face long odds, however. FIFA President Gianni Infantino has maintained a close alliance with President Trump throughout the run-up to the tournament, awarding him the inaugural FIFA Peace Prize in December and rejecting Iran’s earlier requests to move its group-stage matches to Mexico or Canada.

Secretary of State Marco Rubio had raised concerns about the visa process in April, warning against allowing members of the Islamic Revolutionary Guard Corps into the country. Military service is mandatory for men in Iran, and some players on the squad previously served in the IRGC.

Iran opens World Cup play against New Zealand on June 15 at SoFi Stadium in Southern California.

Read more: Iranian officials claim say U.S. denied visas for team staff ahead of World Cup