A rally in Athens to support the pro-democracy movement in Syria. (Louisa Gouliamaki — AFP/Getty Images)

Clinton will hold the meeting in Geneva, where she will also deliver a human rights speech at the U.N. Human Rights Council.

A senior administration official said that all seven of the opposition figures who will meet with Clinton live outside of Syria. Opposition leaders inside the country, the official said, are reluctant to leave for fear they will not be allowed to return.

U.S. officials have gradually opened up to engagement with members of the Syrian opposition, following an initial reluctance to meet with a movement whose leadership remained unclear.

Over the summer, Clinton met with a small group of Syrian activists at the State Department and, in a brief statement afterward, said she had encouraged them to work closely with opposition leaders inside Syria to create a “unified vision” for reform.

U.S. officials have sought to support a transition to democracy in Syria while resisting calls for direct intervention. It wasn’t until August that administration officials explicitly called for President Bashar al-Assad to step down.

Clinton, who is on a five-day trip to Europe, was in Bonn, Germany, Monday for an international conference on Afghanistan.

On Tuesday morning, before travelling to to Geneva, she will address the Organization for Security and Cooperation in Europe, whose election monitors issued a critical report on irregularities in last weekends Russian election.

After Geneva, she attends a meeting of NATO foreign ministers in Brussels, and delivers a speech on Internet freedom in The Hague.