Syria and Iraq have restored diplomatic relations after a nearly quarter-century break.
Iraqi officials say ties were normalized on Tuesday during a visit by Syrian Foreign Minister Walid Muallem to Baghdad.
Iraqi Foreign Minister Hoshiyar Zebari say the two nations discussed ways to boost security and block foreign fighters from entering Iraq from Syria.
In Washington, a U.S. National Security Council spokesman, Gordon Johndroe urged Syria to show its commitment to enforcing security on the border with Iraq.
Meanwhile, Iraqi officials say President Jalal Talabani will travel to Tehran on Saturday to meet Iranian President Mahmoud Ahmadinejad.
Iraqi Foreign Minister Zebari told CNN television that the talks will focus on improving security in Iraq. He denied reports Syrian President Bashar al-Assad will join the talks.
In Baghdad, U.S. and Iraqi forces killed three people in a raid in the Sadr City neighborhood.
The U.S. military says seven suspects were captured in the operation, including an individual believed to have information about an American soldier abducted in October.