WASHINGTON – President Barack Obama on Friday nominated Massachusetts Sen. John Kerry, one of Washington's most respected voices on foreign policy, as his next secretary of state.

The move is the first in an expected overhaul of Obama's national security team heading into his second term.

As the nation's top diplomat, Kerry will not only be tasked with executing the president's foreign policy objectives, but will also have a hand in shaping them. The longtime lawmaker has been in lockstep with Obama on issues like nuclear non-proliferation, but ahead of the White House in advocating aggressive policies in Libya, Egypt and elsewhere that the president later embraced.