Election officials are counting ballots in Turkey's presidential runoff vote after polling stations closed at 5 p.m. on Sunday.

The outcome of the contest between incumbent Recep Tayyip Erdogan and rival Kemal Kilicdaroglu is expected to be close.

Neither of them secured the majority needed to win outright in the first round of voting on May 14.

Erdogan has highlighted his achievements as prime minister and president over the past 20 years. He has also touted a deal that he helped broker between Russia and Ukraine, which enables Ukrainian farm products to be exported via the Black Sea.

Erdogan voted in Turkey's largest city, Istanbul. He said he prays to God that the election will benefit the country and its people.

Kilicdaroglu is the head of the largest opposition party and the joint candidate of six opposition forces. He has criticized Erdogan's economic measures and accused the president of governing with an iron fist.

Kilicdaroglu cast his ballot in the capital, Ankara. He said he trusts people's common sense and that the country will surely have democracy and freedom.