Turkey's prime minister is scheduled to meet a group of activists involved in the country's biggest anti-government protests in decades.
Recep Tayyip Erdogan's talks will come after clashes in Istanbul lasted into the early hours, as riot police fired tear gas, water cannon and rubber bullets at protesters in the city's central Taksim Square and its adjacent Gezi Park.
Police also used tear gas to disperse protests in the capital, Ankara.
The protests erupted on May 31 after a violent police crackdown on a peaceful sit-in by activists objecting to a project replacing the park with a replica Ottoman-era barracks.
Throughout the protests, Mr Erdogan has maintained a defiant tone, insisting he would not be bowed by what he described as a vocal minority. As police clashed with protesters in Taksim, he insisted again that the unrest was part of a conspiracy against his government.
The demonstrators, he said, "are being used by some financial institutions, the interest rate lobby and media groups to (harm) Turkey's economy and (scare away) investments".
A peaceful demonstration against the park's redevelopment that began more than two weeks ago has grown into the biggest test of his authority, sparked by outrage over the violent police crackdown on May 31.
The unrest has spread to 78 towns and cities across the country, with protesters highlighting their objections to what they say is the prime minister's increasingly authoritarian style and his perceived attempts to impose a religious and conservative lifestyle on a country with secular laws - charges he rejects.
Four people have been killed, including a policeman, and about 5,000 have been treated for injuries or the effects of tear gas, according to the Turkish Human Rights Foundation.