Iran says a U.S. attack is unlikely since Washington has been overwhelmed by its problems Iraq and Afghanistan.

Iran's Foreign Ministry spokesman Mohammad Ali Hosseini says it is "unlikely" that U.S. forces embroiled in Iraq and Afghanistan would be able to invade a new country, adding it would have unpleasant consequences for the region and the world.

Last week both Adm. Mike Mullen, chairman of the U.S. Joint Chiefs of Staff, and Defense Secretary Robert Gates accused Iran of stepping up its military support for Iraqi militias and said that all military options to deal with the situation were on the table.

Hosseini's remarks, which came at his weekly briefing Sunday, also ridiculed recent U.S. accusations of Iran supplying arms to Iraqi militias.