The mandate given to Israeli parliament speaker Benny Gantz to form a government expired on Thursday, but talks were reportedly ongoing on an emergency alliance with his rival, Prime Minister Benjamin Netanyahu.
Gantz, a centrist and Israel's former army chief, had been given a deadline of midnight by President Reuven Rivlin to reach a deal with Netanyahu.
Rivlin had said that if the sides failed to strike an accord, he would mandate Israel's parliament to select a candidate to form a government, a move that would likely prolong the country's unprecedented political deadlock.