Syria's ambassador to Iraq, Nawaf Fares, has defected and says he has joined the revolution.

In a statement broadcast on the Arabic-language television network Al-Jazeera, Fares announced he is resigning from the ruling Ba'ath Party. He said the government has used it as a tool to oppress the Syrian people and their aspirations to freedom and dignity.

He urged members of the military to join him, saying there is no honor in killing one's own people. It was not made clear where Fares was speaking.

He is the highest-ranking Syrian official to flee Bashar al-Assad's government since the deadly rebel uprising began 16 months ago.

In Washington, White House spokesman Jay Carney called this a sign that support for Mr. Assad is crumbling both inside his own government and internationally.

Earlier, United Nations envoy Kofi Annan said that in his talks this week with President Assad, the Syrian leader proposed a negotiator who would represent him in talks with the opposition. Mr. Annan did not reveal a name.

Mr. Annan also said Iran and Iraq told him they would use their influence to push the Syrian opposition into talks. Carney said the United States is not excluding anyone from participating in talks about Syria's future, but he doubts Iran could play a constructive role.