Updated

TEHRAN, Iran -- Iran's Foreign Ministry spokesman has denounced the deployment of a Saudi-led military force to Bahrain to prop up the monarchy in the tiny island nation against widening demonstrations by the Shiite-led opposition.

Ramin Mehmanparast said on Tuesday that the "presence of foreign forces in Bahrain is unacceptable" and would only complicate the crisis in the Sunni-led kingdom.

The statement is the strongest reaction from Shiite powerhouse Iran on Monday's deployment of about 1,000 troops from Saudi Arabia and other members of the Gulf Cooperation Council.

Bahrain is a key U.S. ally and host of the U.S. Navy's 5th Fleet. Its government is increasingly at odds on how to quell escalating opposition demonstrations, inspired by the wave of protests gripping the Arab world since December.