WASHINGTON — John F. Kerry arrived at State Department headquarters Monday morning to begin his new role as secretary of State, telling employees that he wanted to answer the question: “Can a man actually run the State Department?”

The former Massachusetts senator, who was preceded in the post by Hillary Rodham Clinton and Condoleezza Rice, acknowledged that “I have big high heels to fill.”

Kerry addressed the troops from the staircase rising from the headquarters lobby, the exact spot where Clinton gave good-bye remarks to a rapturous foreign service crowd last Friday. Kerry also drew an appreciative audience, including one man who held up a sign that read: “Welcome JFK.”

Kerry brought up the partisan fight over the terrorist attack that killed four Americans in Benghazi, Libya, last September, promising that “I will not let their patriotism and bravery be obscured by politics.” He said everything he’ll do in the job “will be focused on the security and safety of our people.”

Kerry, who has long coveted the role of America’s top diplomat, said he viewed the State Department as a place where “we can do the best of things that you can do in government,” including trying to make peace.

Kerry began making calls to a long list of foreign leaders over the weekend, including Prime Minister Benjamin Netanyahu and Palestinian Authority President Mahmoud Abbas.