U.S. Secretary of State John Kerry insisted on Friday that Syrian President Bashar al-Assad has no place in Syria’s future and said the United States was not without options on stepping up pressure on him.

U.S. Secretary of State John Kerry insisted on Friday that Syrian President Bashar al-Assad has no place in Syria's future and said the United States was not without options on stepping up pressure on him.

"I believe as we begin to get to Geneva... that it will become clear there is no political solution whatsoever if Assad is not discussing a transition and if he thinks he is going to be part of that future. It is not going to happen," Kerry told a news conference after meetings with his Canadian and Mexican counterparts.

"We are also not out of options with respect to what we may be able to do to increase the pressure and further change the calculus," he added.

Kerry's comments come as Syrian opposition groups vote on whether to attend the U.N.-sponsored talks in Montreux, Switzerland.

Syria was hit by a violent unrest since mid-March 2011, where the Syrian government accuses foreign actors, mainly the Saudi Arabia and Turkey, of orchestrating the conflict by supporting the militant opposition groups with arms and money.