Russia is sending planes to Syria to evacuate its citizens, ahead of expected US air strikes.

Iran's foreign minister Mohammed Zarif today slammed potential airstrikes against Syria as "illegal" under the United Nations charter. 

Earlier US Secretary of State John Kerry met foreign ministers from the Arab League in Paris this afternoon as part of America's diplomatic offensive to win backing for military strikes in Syria.

It's reported the Pentagon is now preparing for a longer operation than previously thought. 

The Los Angeles Times is reporting that the US military will carry out three days of missile strikes against 50 Syrian government targets.