Pentagon: 2 U.S. Navy Boats Held by Iran Military

Iranian military forces seized two U.S. Navy boats and are holding them in custody on the Irans Farsi Island in the middle of the Persian Gulf, U.S. officials told NBC News.

Officials said it's unclear whether the 10 American sailors who were aboard one of the small riverine boat had strayed into Iranian territorial waters before they were captured. But

The officials said the Americans were on a training mission when their boat experienced mechanical difficulty and drifted into Iranian-claimed waters and were seized by Iranian Coast guard.

Secretary of State John Kerry has been on the phone with Iranian officials in Tehran attempting to gain the release.

One senior official told NBC News the Iranians understand it was a mistake and have agreed to release the Americans in international waters within hours.