Sen. Bob CaseyBob CaseyTim Kaine backs call to boost funding for Israeli missile defense The Trail 2016: The newrevolution begins Liberal group: Kaine could be 'disastrous' VP pick MORE (D-Pa.) is pushing the Obama administration to use the upcoming Syria peace talks to work toward a deal that requires President Bashar al-Assad to step aside.
"Bashar al-Assad and the oligarchs that surround him have long since lost any legitimacy as the leaders of Syria, but we need not accept the false choice he has presented the world: his continued rule, or the rule of ISIS," Casey wrote in a letter sent Thursday to Secretary of State John Kerry and U.N. Ambassador Samantha Power.
Casey's letter comes ahead of scheduled talks in Geneva to try to find a way to end Syria's four-year civil war, after the last round of negotiations fell apart in 2014.
Casey added that while he was glad the United States was restarting the talks, "a negotiated political solution that ends the rule of Bashar al-Assad, the greatest magnet for ISIS recruiting, and his inner circle, must be reached."
The Obama administration has long called for a transition of power to be included as part of any Syria deal. Kerry doubled down on that earlier this week, saying that "we've said 100,000 times Assad cannot be part of the long-term future of Syria."
But the president is gaining skepticism from Syrian opposition members, who worry that the administration will give into demands that Syria create a "national government," which they say would allow Assad to run for reelection.
Casey added in his letter that he was "appalled" by reports the United Nations revised a humanitarian aid document after consulting with the Assad regime. BuzzFeed reported earlier this month that changes were made — including the removal of the words "besieged" and "siege" — after a draft was sent to the Syrian government.
"I urge you to insist that UN-produced assessments and humanitarian aid plans accurately reflect conditions on the ground, not the political concerns of the Assad regime, which is responsible for most of this humanitarian crisis," Casey wrote in Thursday's letter.