Diplomatic sources said Jolie and Guterres would tour the refugee camps in the southeastern province of Gaziantep. They are also scheduled to hold official talks with Turkish officials in Ankara on Friday.
Last year, the American actress visited Syrians taking refuge in the border province of Hatay, and praised Turkey for welcoming the refugees.
Jolie's visit comes after her visit to a camp in Jordan where Syrian refugees fleeing conflict in their home country are being accommodated.
Speaking after meeting a group of female refugees at the Zaatari camp, which hosts about 30,000 Syrians displaced by the 18-month conflict, Jolie said, “I am very concerned, the world is very concerned,” explaining her drive to focus international attention on the plight of Syrian refugees and to attract more funding to help them.
“What is very heartbreaking is when Syrian people ask you why you think no one is able to find a solution for them,” Jolie said.
Jolie met with Syrian refugee women and also visited the border late on Monday to talk with Syrian refugees as they crossed into Jordan.
“What they described on the ground, hearing it from them is so horrific,” she said, adding that the children's stories were especially moving, including that of one child who described having witnessed people being pulled apart “like chickens.”
“When you meet so many innocent people and civilians, the people of Syria are asking who is on their side. ‘Who is going to help us as the months go on?'” she added.
Hundreds of thousands of Syrians have fled the chaos and increasing violence of the uprising against President Bashar al-Assad, with activists saying at least 23,000 people have died since the conflict began in March 2011.
According to Guterres, Jordan alone has taken in some 200,000 Syrians -- the largest number in the region. Both the UN High Commissioner for Refugees (UNHCR) and Jordan say the figure reflects the actual numbers of Syrians housed in the kingdom, as opposed to the smaller figure of Syrian refugees who have registered with the UNHCR or who are awaiting registration.