US Vice President Joe Biden said Saturday the US and its partners were pushing to help strengthen the Syrian opposition, insisting Syrian President Bashar al-Assad was a "tyrant" and must go.
Biden was speaking on the second day of security talks in the German city of Munich, where he is later due to hold talks on Syria with Russian Foreign Minister Sergei Lavrov and Syrian opposition chief Moaz al-Khatib.
The US has provided "more than $50 million in non-lethal assistance to the Syrian opposition and are working alongside our partners to help them become more inclusive and cohesive," he said.
But he referred to recent comments by US President Barack Obama, saying, "We are under no allusions, the days ahead will continue to be very difficult but the opposition continues to grow stronger".
"President Obama and I, and nearly all of our partners and allies, are convinced that President Assad, a tyrant, hellbent on clinging to power, is no longer fit to lead the Syrian people and he must go," Biden said.
"We can all agree... on the increasingly desperate plight of the Syrian people and the responsibility of the international community to address that plight," he added.
He said it was "no secret" that Russia and the United States have "serious differences" on issues such as Syria.