Syria's ambassador to Iraq has defected and joined the opposition to President Bashar al-Assad's rule.

In a statement broadcast on the Arabic-language television network Al-Jazeera, Nawaf Fares urged members of the military to join him, saying there is no honor in killing one's own people.

He also said the government has used the ruling Ba'ath party as a tool to oppress the Syrian people and their aspirations to freedom and dignity.

The Syrian foreign ministry said in a statement Thursday that Fares has been relieved of his duties and no longer has relations to the ministry or the embassy in Baghdad.

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

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