"I intend to speak with everyone," Gantz said early on Wednesday at Blue and White headquarters addressing to his supporters.
Gantz said that he had already spoken with the leaders of several other parties, adding that he would also talk to Israel's former Defence Minister Avigdor Lieberman, the leader of the nationalist secular Yisrael Beiteinu party.
Lieberman earlier said that a wide coalition of his Yisrael Beiteinu party, Blue and White alliance and the incumbent Prime Minister Benjamin Netanyahu's right-wing Likud party was the only option to form the government.
On Tuesday, Israel held the snap general election to its 120-seat unicameral parliament, the Knesset. Exit polls showed no clear winner at the ballot. According to exit polls, Blue and White alliance led by Benny Gantz can count on 32-34 seats, while Likud can gain 31-33 seats. Yisrael Beiteinu may receive 8-10 seats in the parliament.
Without Lieberman's support, a potential right-wing coalition led by Likud could control up to 57 seats, while an opposition coalition led by Blue and White could gain no more than 58 seats. It means that both leading political forces are falling short of the 61 seats needed for a governing majority.