Brahimi made stops at the Altinoz refugee camp in Turkey and the Za'atari camp in Jordan to see firsthand the struggles facing many of the hundreds of thousands of Syrians who have fled the civil war in their homeland, a U.N. release said.
"He was deeply moved by what he saw and heard and promised to convey an accurate picture of their plight to all those whom he will meet at the United Nations in New York, where he will be next week," U.N. spokesman Martin Nesirky said.
Brahimi was briefed by officials of U.N. agencies and government officials on conditions in the camps.
Brahimi, who took on the envoy's role this month, toured the camps after meeting Saturday with President Bashar Assad in the Syrian capital Damascus.
"This crisis is becoming worse by the day," Brahimi told reporters after that meeting.
The U.N. High Commissioner for Refugees says more than 260,000 Syrian refugees have been registered in neighboring countries since the uprising against Assad began in March 2011. Thousand of Syrians have died in the conflict.