Kerry has said the number of states ready to take military action against Syria's government is in the "double digits".
Kerry, who is in Europe for a four-day visit, met his French counterpart Laurent Fabius in Paris, where both men spoke of their determination to respond to the use of chemical weapons in Syria.
A poll commissioned by the BBC and ABC News suggested more than a third of Congress members were undecided whether or not to back military action - and a majority of those who had made a decision said they would vote against the president.
http://www.bbc.co.uk/news/world-europe-24004836