U.S. officials have meanwhile issued further comment on the threats that they say Iran and Syria pose to the international community.
Syrian Prime Minister Naji al-Otari, on a visit to Tehran yesterday, spoke of challenges faced by Iran and Syria and of a "common tie" between the two countries.
"When such issues are intensified between Syria and Iran, then a common tie is formed [between the two countries] in developing their relationship," al-Otari said.
Iranian Vice President Mohammad Reza Aref, who met with the Syrian prime minister, said Iran was ready to help Syria "on all grounds to confront threats."
No threats were named specifically.
In Washington, Porter Goss, the director of the Central Intelligence Agency (CIA), told a U.S. Senate hearing that Iran continues to support terrorist groups such as Hezbollah and continues to hold some members of Al-Qaeda. He also spoke of concerns about Iran's nuclear program and its pursuit of long-range ballistic missiles.
U.S. Secretary of State Condoleezza Rice and Defense Secretary Donald Rumsfeld each criticized Syria for not helping the United States in Iraq and for occupying Lebanon.
Washington has withdrawn its ambassador
to Syria over the 14 February assassination
of former Lebanese Prime Minister Rafiq Hariri, who was an outspoken critic of Syria's military presence in his country.