The United States Monday condemned what it called a "terrorist" assault on Syrian regime forces who came under fire after crossing into Iraq last week in an attack claimed by an Al-Qaeda group.

"Any kind of attack like this, any kind of terrorism like this is something that we should condemn," State Department spokeswoman Victoria Nuland said.

Al-Qaeda front group the Islamic State of Iraq claimed the attack on a convoy in west Iraq that killed 48 Syrian soldiers and nine Iraqi guards, in a statement posted on jihadist forums on Monday.

The soldiers, who were wounded and received treatment in Iraq, were being transported through the western province of Anbar on their way back to Syria when the attack took place on March 4, according to the Iraqi defense ministry.

Nuland has rarely denounced as "terrorist" the attacks by Syrian opposition forces on the troops of President Bashar al-Assad, who the United States wants to see step down.

But she defended her choice of words, saying "any time you attack noncombatants in this way -- and the techniques were obviously terrorist tactics -- we're going to call it what it is."

Nuland also renewed Washington's concerns about Al-Qaeda and its affiliates "trying to take advantage of the violence and chaos in Syria for their own ends, which are not in keeping with the desires of the Syrian people to live in a just and democratic society."