Senate Foreign Relations Committee Chairman Joseph R. Biden Jr. on Monday defended his proposal for decentralizing the government of Iraq against criticism by Iraqi politicians and a rare rebuke from the U.S. embassy in Baghdad.

“It is not partition, it is not foreign imposition,” the Delaware Democrat, who is running for president, told reporters in a conference call. “A federal Iraq is a united Iraq.”

The Senate voted 75-23 on Sept. 26 to adopt Biden’s non-binding “sense of the Senate” amendment to the fiscal 2008 defense authorization bill (HR 1585) calling for Iraq to be divided into Shiite, Sunni and Kurdish “federal regions,” with a weak national government to facilitate sharing of oil revenue.

The move drew criticism from Iraqi politicians, including Prime Minister Nouri al-Maliki, and from the U.S. embassy in Baghdad, which posted an unsigned statement on its Web site Sunday.

“The embassy wishes to make clear that it remains the firm policy of the American administration to support a stable, secure, and unified Iraq,” the statement said.

“As we have said in the past, attempts to partition or divide Iraq by intimidation, force or other means into three separate states would produce extraordinary suffering and bloodshed. The United States has made clear our strong opposition to such attempts.”