"The two leaders discussed the importance of non-violence and of the rights to free expression and assembly and a free press," the White House readout of the conversation said Tuesday.
In Ankara Tuesday, police arrested about 20 people in raids at 30 sites, accusing them of terrorism linked to the Gezi Park protests, officials said.
Ankara police said they used surveillance footage to identify suspects linked to terrorist groups that participated in the protests and are suspected of "attacking police and the environment," Today's Zaman said.
About 2.5 million protesters took to the streets in Turkey last month to protest plans to demolish Istanbul's Gezi Park and build a shopping complex. What started out as a protest to save the park grew into violent anti-government protests that spread across the country.
Obama and Erdogan also discussed the crisis in Syria, including the use of chemical weapons by President Bashar Assad's regime against Syrians.
Concerning Syria, the leaders discussed "the need to provide additional support to the Syrian Coalition and the Supreme Military Council to improve their effectiveness, and the importance of close bilateral cooperation on contingency planning and counterterrorism efforts," the readout said.