Romanian Prime Minister Victor Ponta is leading on Sibiu Mayor Klaus Iohannis in the first round of the country's presidential elections on Sunday.

The two candidates with the biggest result in the Romanian will face a run-off on November 16 after becoming the only two candidates with more than six percent of the vote.

With more than half of the votes counted, Ponta's support is at 39.6 percent, while Iohannis has 30.2 percent of the ballots cast in his favor, according to Romania Insider.

Incumbent Traian Basescu cannot run of a third consecutive term in office.

Elena Udrea, the candidate he personally backed, is lagging far behind Ponta and Basescu.

Turnout was reported to be 52.3 percent of the nearly 18 million Romanians eligible to vote.

Some observers say results make the poll's next round too close to call, with the outcome tied to the choice of those who backed other candidates and undecided voters.

Pollsters however suggest Ponta will narrowly win the run-off.