Kyriakos Mitsotakis said Greece needs a strong leadership in this "extremely unstable world" / Photo: AP

Greece is set to hold early elections on May 21, the country's prime minister announced.

If a clear majority is not secured in the first round of the elections, a second round will be held by early July, said Kyriakos Mitsotakis on Tuesday in introductory statement during​​​​​​​ a weekly cabinet meeting.

Mitso takis argued that the government has a duty to expose faults of the current simple proportional election system, which he said is tended to produce instability.

The first ballot will determine who will govern, while the second round will determine how to govern, he said, adding that Greece needs a strong leadership in this "extremely unstable world."

"This is why citizens should know who they are voting for as prime minister," he said.

Mitsotakis urged citizens to vote for his conservative Nea Dimokratia (ND) party to form a single party government.

"Greek men and women in the elections of May 21 will finally choose whether the country will continue to claim and win the bet of modernization," he said.

Alexis Tsipras, leader of the leftist main opposition SYRIZA-PS, on Monday reiterated that he favors a coalition of leftist parties, led by SYRIZA, for "regeneration and re-construction," of the country.

He, however, ruled out a scenario of grand coalition with the ruling ND party.

“What kind of program agreement can be achieved by a party that forms the core of the neoliberal point of view, with parties that call themselves progressive," Tsipras said .