U.S. President Barack Obama has asked Congress for $500 million to train and arm vetted members of the Syrian opposition.
The military training program would deepen the Obama administration's involvement in the more than four-year conflict between rebels and forces loyal to Syrian President Bashar Assad.
The Syria program is part of a broader $65.8 billion overseas operations request that the administration sent to Congress on June 26.
The requests come as Obama faces fresh criticism of his policies in Syria, which some White House opponents contend allowed the Sunni insurgency pressing through Iraq to gain strength.
Earlier this year, Obama suggested he was seeking ways to boost assistance to moderate Syrian rebels who are struggling to make gains in their clashes with Assad's forces.