Kerry told reporters after meeting with Jordanian Foreign Minister Nasser Judeh at the State Department that he hoped Assad could be convinced to enter into a negotiated solution with the Syrian opposition that would end almost two years of bloody violence that has killed nearly 70,000 people and move forward with true democratic reform.
"We need to address the question of President Assad's calculation currently. I believe there are additional things that can be done to change his current perception," he said, adding: "I've got a good sense of what I think we might propose."
Kerry did not elaborate on the ideas and pointedly offered no guarantee of success, particularly since Assad has defied calls to step down and clung to power throughout the crisis that has grown increasingly desperate. But, Kerry said his priority was to find a peaceful resolution to the conflict.
"I can assure you my goal is to see us change his calculation, my goal is to see us have a negotiated outcome and minimize the violence," he said. "It may not be possible. I am not going to stand here and tell you that's automatic or easily achievable.
The former chairman of the Senate Foreign Relations Committee said he would be discussing his ideas with officials when he visits Europe and the Middle East beginning in the last week of February.
As a senator, Kerry had floated several ideas for ramping up the pressure on Assad, including creating protected safe zones for regime opponents and arming the rebels fighting to oust him
State Department spokeswoman Victoria Nuland said the administration's position remains that supplying weapons would only exacerbate the killing. She said the United States would continue to provide only non-lethal and humanitarian assistance to the opposition.
She did, however, say that Assad is living in a "fantasy world" if he thinks he can survive the ongoing rebellion.
Kerry is a longtime friend of Judeh, the Jordanian foreign minister, whose country is deeply concerned not only with the situation in Syria and the status of the Assad regime's chemical weapons stockpiles, but also the nearly moribund Middle East peace process.
Judeh said he was pleased that President Barack Obama and his administration were committed to trying to achieve a lasting settlement to the Israeli-Palestinian conflict and urged action to try to restart peace talks.
Kerry's trip to the Mideast will lay the groundwork for a visit to Israel, the Palestinian territories and Jordan by Obama in the spring. But Kerry warned against expecting major developments, noting that it could be "arrogant" to propose a new formula for negotiations before hearing from leaders in the region.
"The president is not prepared at this point in time to do more than listen to the parties, which is why he has announced he is going to go to Israel," Kerry said. "That affords him an opportunity to listen.
"I think we start out by listening and get a sense of what the current state of possibilities are, and then begin to make some choices," he said. "It would be a huge mistake, almost an arrogant step, to suddenly be announcing this and that without listening first."
Yet, he stressed that the administration was ready "to explore every possibility" for peace.
"The window is closing on this possibility, the region knows it," Kerry said. "It deserves our utmost consideration and it will get that."