The US Secretary of State's remarks come ahead of his visit to Moscow next week.
President condemns Khan Sheikhoun attack that killed 73 as 'an affront to humanity'.
Republican has said that White House policy had emboldened the Syrian dictator.
Residents say the terror group is a reduced presence in the city as the US-led coalition prepares to attack.
More than 70 people died after an alleged chemical weapons attack by the Syrian government.
Sarin was allegedly used but Syria 'categorically denies' the claim.
As the White House struggles to explain its Syria policy, France calls for clarity on the US position.
When Britain and others decided to take no military action against Assad, he knew he could act with impunity.
With multiple infringements occurring every day, one has to wonder whether there is a ceasefire in place at all.
Up to 58 people are believed to have died in the attack on Syrian town of Khan Sheikhoun.
Nanoparticle-wrapped enzyme can be administered before exposure to nerve gas and pesticides in mice.
The attack on Tuesday happened in the town of Khan Seikhoun, in rebel-held Idlib.
St Petersburg is the latest in a string of attacks against Russia at home and abroad.
Ibrahim Al-Ansari's death will disrupt Isis' ability to recruit young people and children, coalition spokesman Scrocca said.
New policy represents marked departure from Obama administration's stance on the conflict.
More than half of the Syrian population has been displaced at some point during the conflict.
General Joseph Votel highlighted the challenges in Iraq, Syria, Afghanistan, Yemen, Egypt and Pakistan.
Militants returning to Britain from conflict zones pose increased terror threat, claims expert.
UN has warned that flooding from the dam could be "potentially catastrophic" for those areas downstream.
People do not start out violent, but inequality, injustice and violence leaves them ripe for extremist groups.
FBI ready to protect Watson after president says ruling against his executive order is 'judicial overreach'.
The location was seized by Isis in 2013 and has been used as HQ, prison and training centre.