WASHINGTON (AP) -- The Senate is on track to confirm President Barack Obama's pick to run the Pentagon.
A vote is scheduled for Thursday afternoon on Ashton Carter's nomination. If confirmed, Carter will be Obama's fourth defense secretary in six years.
He will replace Chuck Hagel, the Vietnam War veteran and former Republican senator who struggled with Obama's tight-knit group of national security advisers.
The 60-year-old Carter -- a physicist by training -- served as the Pentagon's second-ranking official from 2011 to 2013.
As defense secretary, he will face the unenviable task of steering the nation's military as the United States tries to defeat Islamic State militants, stop Russian-backed separatists in Ukraine and wind down the war in Afghanistan. He also will face smaller Pentagon budgets.