The weekend remarks by the top US envoy were quickly clarified when his spokeswoman said Washington's policy was unchanged and Assad had no role in Syria's future.
But in Damascus, local media touted Kerry's remarks as a reversal of US policy, even though Assad said he was waiting to see whether they would followed by action.
"We are still listening to the comments and we have to wait for the actions and then we'll decide," the Syrian leader told Iran television in remarks carried by Syrian state media.
Assad has long accused Washington of "supporting terrorism" because of its backing for the Syrian opposition, and repeated Monday that any shift in policy required an end to that.
"We have no choice but to defend our country," he added.
"Any international changes that come about within that framework are something positive, if they are honest and have an effect on the ground."
He was speaking after Kerry said in an interview broadcast Sunday that Washington could negotiate with Assad.
"Well, we have to negotiate in the end," he said, when asked by CBS television if he would negotiate with Assad.
Kerry stressed that any negotiations would be in the context of the Geneva communique, a document produced after a first round of talks between government and opposition that calls for a transitional governing body with full executive powers, but makes no mention of Assad's future.
""This is a new recognition of President Assad's legitimacy, his key role and his popularity, and the resulting necessity of negotiating with him," the daily said."
Syria's government insists Assad's departure from office is not up for discussion, while the opposition and its backers have long insisted he can have no role in the country's future .
In the interview, Kerry made no reference to Assad's future, but said pressure was being applied on the leader to bring him to the negotiating table.
Kerry's spokeswoman insisted his comments were consistent with US policy, but Syrian media said they underlined the "failure" of Washington's policy towards Syria and acknowledgement that Assad will not be ousted militarily.
"Facing a fait accompli, the American administration has backed down and recognised the need to reposition its policy on the Syria crisis," wrote Al-Watan.
This is a new recognition of President Assad's legitimacy
"his key role and his popularity, and the resulting necessity of negotiating with him," the daily said.
The newspaper suggested Kerry's comments could pave the way for American participation in talks on the conflict hosted by Russia next month.
Kerry's comment drew consternation from some in the Syrian opposition.
Kerry's remarks come after CIA head John Brennan also warned that Washington feared that a chaotic collapse of Syria's government could usher in an Islamist takeover.
On the ground, activists said Kerry's remarks came as no real surprise.