Donald Trump does not want to expand the nuclear arsenal of the United States, but instead advocates bringing the nation's nuclear capabilities into the modern day, James Woolsey, an advisor to the president-elect on national security, told CNBC on Friday.

Woolsey, an ex-director of Central Intelligence and a former nuclear arms treaty negotiator, said in a "Squawk Box" interview, "I think he's right because we have been degrading our nuclear capability over the last eight years." He added he does not think there's any commitment on the part of Trump to increased numbers of nuclear weapons.