On the eve of the Latin Grammy (search) awards in Miami, nominated Cuban musicians still had not received U.S. visas Tuesday — a headache alternately blamed on politics and red tape.

Twelve Cuban acts — including singer Ibrahim Ferrer (search) of the Buena Vista Social Club (search), pianist Chucho Valdes (search) and the popular group Los Van Van (search) — have been nominated for the awards, to be presented Wednesday night in a nationally televised ceremony.

Since Cuba is classified by the U.S. government as a state sponsor of terrorism, more extensive background checks are required for citizens of the communist island who apply for visas. The process can take from eight to 10 weeks.

Officials in Cuba's Culture Ministry said earlier this month that they began the process of seeking approvals for nominees on Aug. 2. No one could be reached for comment Tuesday at the Cuban Music Institute, which operates under the Culture Ministry. Officials from Cuba's foreign relations ministry did not immediately respond to requests for comment Tuesday.

The U.S. Interests Section received seven visa applications three weeks ago, on Aug. 12, a U.S. government official said Tuesday, speaking on condition of anonymity.

Three of the seven applications have been denied, and four others are still pending, the official said. The identities of those who were denied is confidential information. But a State Department official in Washington, who also spoke on customary condition of anonymity, told The Associated Press that no visa applications had even been received from Ferrer and Valdes.

State Department spokesman Richard Boucher said Tuesday the primary reason four Cuban nominees still haven't heard if they can travel to Miami is that they applied at the last minute.

"Everybody knows ... that it can take six to eight weeks to process applications," he said.