BEIRUT, Lebanon — President Bashar al-Assad of Syria told the United Nations special envoy, Lakhdar Brahimi, on Wednesday that no political solution could be reached in Syria without an end to international support for the fighters battling his government, underscoring how far apart the sides remain as global powers try to arrange peace talks next month.

“The success of any political solution is tied to stopping support for terrorist groups and pressuring their patron states,” Mr. Assad told Mr. Brahimi, the joint special representative from the United Nations and the Arab League, in Damascus during their first meeting in nearly a year, Syrian state television reported.

“Only the Syrian people are authorized to shape the future of Syria,” Mr. Assad said.

The talks, known in diplomatic shorthand as Geneva 2, are intended to start a political process that would result in a transitional government. But the sponsors — the United States, which supports the opposition, and Russia, which supports Mr. Assad — remain divided on whether that transitional government could include Mr. Assad.

And Mr. Assad and his opponents have laid out incompatible preconditions, with the main exile opposition group saying it will not attend the talks unless Mr. Assad’s departure is guaranteed, and Mr. Assad saying he will not talk with them unless they put down their arms. The opposition, too, is fractured, with many rebel groups saying they reject the Geneva talks as well as the exile leaders who are their nominal representatives.