The United States is preparing to announce new sanctions targeting Syria and other entities supporting President Bashar al-Assad's government, a senior U.S. official said on Friday, August 10, Reuters reported.

"We will be tightening even further with additional sanctions that drive at both Syrian entities and those who are supporting the efforts of the Syrian government to oppress its own people," the official told reporters travelling with U.S. Secretary of State Hillary Clinton in Ghana.

The official said the new measures, which were expected to target Assad's government as well as possibly Iranian entities that the United States accuse of assisting Assad, would be announced in Washington later on Friday.