Ahmed al-Jarba, the head of the main Syrian opposition alliance, is to travel to Europe and the United States starting next week, dpa reported according to broadcaster Al Arabiya.
"The talks will focus on arming revolutionaries and the deteriorating humanitarian situation inside Syria," said Louay Mokdad, the spokesman for the Free Syrian Army.
The Syrian National Council's al-Jarba will meet French President Francois Hollande on Wednesday. He is expected to visit London and Berlin before travelling to Washington on July 26.
Al-Jarba, a former political prisoner who is backed by Saudi Arabia, has elected on July 6.
The 115-member coalition groups key opposition figures living in exile and inside Syria. It has, however, been mired in divisions, mainly over proposals to negotiate an end to the conflict with President Bashar al-Assad's regime.
At least 93,000 people have been killed in the Syrian civil war, according to the United Nations.