Kerry is in Doha, where the so-called Friends of Syria group is holding its first meeting since the Obama administration announced plans to arm rebels against Syrian President Bashar Assad, Voice of America reported.
Kerry said diplomats are pushing for a negotiated solution establishing a transitional government for Syria, in the throes of a civil war since March 2011.
"There is a unanimity about the importance of trying to find a way to peace, and not a way to war," Kerry said. "The Assad regime is making that very difficult."
Kerry and British Foreign Minister William Hague have been advocating direct talks in Geneva, Switzerland, between Syria's government and its opponents, a plan that is also backed by the European Union and many Arab countries.
A meeting to try to open talks between Syria's government and rebels, is planned for next month in Geneva under the auspices of the United States and Russia.
French Foreign Minister Laurent Fabius said ministers attending Saturday's meeting in Doha will "try to establish the situation on the ground ... [and] see how we can help the opposition coalition and bring about a political outcome."
French leaders discussed the possibility of Assad ally Iran joining the Geneva talks, but Fabius said anyone at the table must accept the executive powers of a transitional authority, VOA said.
"Iran did not accept the aim of the conference, to take part in it. If the new Iranian president made explicit statements to move in this direction, we will see what the position is," he said.