Updated

Iran invited the U.S. women's badminton team to compete in a tournament then denied its players visas Wednesday, saying there was no time to process their visa applications.

The team's participation in event starting Friday was to have been the first U.S.-Iranian exchange under the Obama administration. The two countries have not had diplomatic relations since the Islamic Revolution and the hostage-taking at the U.S. Embassy in Tehran in 1979.

The U.S. State Department, which sponsored the squad's trip to the Middle East, said it is disappointed that Iran failed to issue visas.

The U.S. team will not participate in the competition due to a "lack of enough time to process" its visas, the spokesman for Iran's Foreign Ministry, Hasan Qashqavi, said Wednesday.

It was not clear when Iran invited the 12-member team or when they had applied for their visas — usually a long bureaucratic process that is complicated for U.S. citizens by the lack of diplomatic relations.

State Department spokesman Robert Wood said Iran has provided no official explanation for not providing the visas, and that the U.S. team had supplied all required paperwork to the Iranians.

Wood said the team is returning to the United States.

The eight players, along with four coaches and managers representing USA Badminton, had been in transit in Dubai as of Tuesday.

The State Department said Monday that the Iranian Badminton Federation had invited the team to take part in the Iran Fajr International Badminton Tournament, and that it hoped to extend an invitation to Iran's national team to come to the United States in July.

Without the Americans, the competition will go ahead with 13 participants including teams from Malaysia, Syria, Pakistan, Afghanistan and Iraq.

More than 250 Iranian artists, athletes and medical professionals have participated in exchange programs in the United States since 2006, the State Department said.

The U.S. has sent 32 athletes to Iran under a sports exchange program launched in 2007, and 75 Iranian athletes and coaches have visited the United States, it said.

Tensions between the countries nevertheless remain high because of Western concerns over Iran's nuclear program and the country's alleged support for Shiite militias in Iraq — a charge that Iran denies.

In late December, the Bush administration expressed grave concern about the detention and interrogation in Iran of a prominent American academic who was participating in an exchange. The incident led the National Academies of Science to suspend educational exchanges with Iranian institutions.