"Nobody ever says never," said Kerry on being asked during an interview on Sunday in Munich, Germany, if he would take part in the elections. He was in German city to attend the Munich Security Conference.
However, Kerry admitted that "I have no scenario whatsoever in my mind" to launch a presidential campaign.
"I haven't thought about it. As you can tell, pretty busy," said the secretary of state who has been on a packed schedule dealing with a series of international crises for President Barack Obama.
Kerry has faced issues such as the negotiations on the controversial Iranian nuclear programme, the normalisation of US-Cuba relations, the Ukraine crisis, tension with Russia and the Islamic State threat.
Kerry: I have no scenario whatsoever in my mind
Kerry, who has been in his current post since 2013, competed once in 2004 as the Democratic Party candidate in the race for the White House, but was defeated by then president George W. Bush.
Kerry does not usually appear in the surveys on possible Democratic candidates for the 2016 elections, headed by his predecessor at the State Department and former first lady, Hillary Clinton, who has still not made her candidacy official.
Other possible aspiring Democrats being considered are Senator Elizabeth Warren, a favourite of the party's left wing, and US Vice President Joe Biden.