New Delhi: The US Senate on Thursday confirmed Ashton Carter as President Barack Obama's next defense secretary. He will now have an unenviable task of steering the military as the United States confronts Islamic State militants besides handling conflicts in Ukraine and other parts of the world.

Carter, 60, served as the Pentagon's second-ranking official from 2011 to 2013, spent two years previously as the department's technology and weapons-buying chief and was assistant secretary of defense when he led a major restructuring of the F-35 fighter jet program.

At his confirmation hearing on Feb. 4, the next Pentagon chief faces a long to-do list for a military looking at reduced budgets and crises worldwide and drive down the cost of new weapons and make sure new technologies are delivered to troops quicker.

He also told lawmakers he was leaning in favor of providing arms to Ukraine but later cautioned that the focus of the international community's efforts to handle the crisis must remain on pressuring Russia economically and politically.

Carter will be Obama's fourth defense secretary in six years, joining a line of succession that began with Robert Gates and included Leon Panetta and Chuck Hagel who resigned under pressure last year.