Speaking during a campaign trip in Nevada, President Obama said Syrian President Bashar al-Assad would be “held accountable” were he to use chemical weapons. Obama also vowed to continue aiding Syria’s armed rebels.

President Obama: “Today we’re also working for a transition so the Syrian people can have a better future, free of the Assad regime. And given the regime’s stockpiles of chemical weapons, we will continue to make it clear to Assad and those around him that the world is watching and that they will be held accountable by the international community and the United States, should they make the tragic mistake of using those weapons. And we will continue to work with our friends and our allies and the Syrian opposition on behalf of the day when the Syrian people have a government that respects their basic rights to live in peace and freedom and dignity.”

Obama’s comments on backing the Syrian opposition come amidst new details on U.S. support for Syria’s rebels. The Wall Street Journal reports the United States has worked behind the scenes to block weapons and oil shipments to Assad’s regime from Iran and passed intelligence to Syrian rebels through the Jordanian and Turkish governments.