The Senate Foreign Relations Committee on Tuesday approved Christopher Hill as President Obama's ambassador to Iraq.

But Hill still faces opposition from some Republicans, including Sens. Sam Brownback, R-Kan., John McCain, R-Ariz., and Lindsey Graham, R-S.C.,

Brownback said he is not yet ready to place a hold on the nomination but he is "exploring other options just short of that."

McCain and Graham wrote a letter to Obama saying Hill lacked the experience in the Middle East and requested that the president nominate someone else.