The US women's badminton team planning to compete in an Iranian competition as part of a cultural exchange have not been granted visas in time, Iran says.
Foreign ministry spokesman Hassan Qashqavi said there was not enough time for the lengthy process before the 14-nation contest starts on Friday.
It was unclear when the Iranian Badminton Federation had invited the US team, nor when applications were made.
Iran and the US have had no diplomatic ties for nearly 30 years.
The sporting trip was part of ongoing attempts to encourage exchanges with Iranian people.
The US State Department had announced the badminton trip on Monday, and the team were expected to arrive in Tehran from Dubai on Wednesday.
However, Mr Ghashghavi told reporters: "The issuing of visa is a time-consuming procedure and this long period made it impossible for them to receive visas.
"Therefore they will not participate in the competition."
It would have been the first such exchange between the US and Iran since President Barack Obama took office last month.
Cultural exchanges between the two nations began in 2006, under President George W Bush.
The US State Department had earlier said it hoped to extend an invitation to Iran's national badminton team to come to the United States in July.
Previously, the Iranian national teams for basketball, water polo, weightlifting, as well as men's and women's national table tennis teams have visited the United States. Members of USA Wrestling have also travelled to Iran to take part in a competition.