ISTANBUL (AP) — U.S. Vice President Joe Biden on Friday called on Turkey to protect freedom of expression at a time when social media websites are routinely shut down and hundreds of academics are facing legal proceedings over remarks criticizing security operations against Kurdish militants in the southeast.  

Biden is in Istanbul for a two-day visit, during which he is scheduled to meet with President Recep Tayyip Erdogan and Prime Minister Ahmet Davutoglu for talks expected to focus on the war against the Islamic State group.

"The more Turkey succeeds, the stronger the message sent to the entire Middle East and parts of the world who are only beginning to grapple with the notion of freedom," Biden told reporters in Istanbul before meeting with a group of representatives from civil society groups.

 "But when the media are intimidated or imprisoned for critical reporting, when internet freedom is curtailed and social media sites like YouTube or Twitter are shut down and when more than 1,000 academics are accused of treason simply by signing a petition, that's not the kind of example that needs to be set," he added.

 Turkish media said he met with the wives of Turkish-Armenian journalist Hrant Dink, who was assassinated in 2007; Diyarbakir Bar Head Tahir Elci, who was killed in crossfire between police and gunmen in November; and Can Dundar, editor-in-chief of a center-left newspaper who was detained after publishing footage purportedly showing state intelligence delivering weapons to Syrian Islamists.

 Last week, more than 1,000 academics issued a declaration denouncing security operations against Kurdish militants in southeast Turkey, which drew strong criticism from Erdogan and prompted prosecutors to begin legal proceedings against the scholars on possible charges of propaganda on behalf of the outlawed Kurdistan Worker's Party, or PKK. 

Biden also met with legislators from the ruling Justice and Development Party, founded by Erdogan, and two opposition parties. He also visited the Blue Mosque in the historic Sultanahmet neighborhood with his wife Jill, granddaughter Naomi and son-in-law Howard? Krein.

The vice-president and his family also visited a nearby landmark obelisk where a Jan. 12 terror attack killed 10 German tourists. Turkish authorities have said a suicide bomber affiliated with the Islamic State group carried out the attack which struck at Turkey's $30 billion tourism industry.