Turkish president Recep Tayyip Erdogan has called a new election a day after a deadline passed for forming a new government, his office said.
A presidential statement did not say when the new elections would be held, but Mr Erdogan has previously said they were likely to take place on November first.
Mr Erdogan is expected to reappoint prime minister Ahmet Davutoglu to form an interim government during a meeting on Tuesday.
The Islamic-rooted ruling party, which Mr Erdogan founded, lost its parliamentary majority in June for the first time since 2002.
Mr Davutoglu’s efforts to form a coalition alliance failed last week, setting the stage for Mr Erdogan to declare repeat elections he is reported to have favoured all along.
Mr Erdogan is thought to have pressed for new elections to give the ruling party the chance to win back its majority and rule alone.
Turkey faces new elections as it is grappling with a sharp increase in violence between security forces and Kurdish rebels and is more deeply involved in the US-led campaign against so-called Islamic State extremists.
The Turkish lira has dropped to record lows against the dollar amid the political uncertainty.
More than 100 people, mostly soldiers and police, have been killed since July in renewed conflict between the outlawed Kurdistan Workers’ Party, or PKK, and the security forces, which has wrecked a two-and-a-half-year-old peace process with the Kurds.
On Monday, PKK militants detonated a bomb on a road near Semdinli town as a military vehicle was passing, killing two soldiers and injuring three others.
Semdinli is near Turkey’s borders with Iraq and Iran.
Two opposition parties have already declared they will not participate in the interim government, leaving Mr Davutoglu with little choice but to form a government made up of independent figures and politicians from the pro-Kurdish party, who would be taking government posts for the first time in Turkish history.