Hours after he spoke, the Turkish military said its F-16 fighter jets had bombed Kurdistan Workers Party (PKK) militants in the southeastern Turkish province of Sirnak, which borders Iraq, in response to an attack on a group of gendarmes.
Turkey last week launched air strikes on PKK camps in northern Iraq following a series of attacks on its police officers and soldiers blamed on the Kurdish militant group.
The PKK has said the air strikes, launched virtually in parallel with strikes against Islamic State fighters in Syria, rendered the peace process meaningless but stopped short of formally pulling out.
"It is not possible for us to continue the peace process with those who threaten our national unity and brotherhood," Erdogan told a news conference in Ankara before departing on an official visit to China.
Western allies have said they recognise Turkey's right to self-defence but have urged the NATO member not to allow peace efforts with the PKK to collapse
An emergency NATO meeting in Brussels on Tuesday offered political support for Turkey's campaigns in Syria and Iraq, and Erdogan signalled Turkey may have a "duty" to become more involved.
For NATO allies, the prospect of Turkey, which borders Iran, Iraq and Syria, fighting a domestic conflict against Kurdish as well as Islamist fighters is a deep concern. But for many in Turkey, Kurdish rebellion remains the primary national threat
Who Are The PKK?
The PKK is an ethno-nationalist, Marxist-Leninist group that was founded in 1974 with the goal of establishing an autonomous state for the Kurdish people in Turkey. Kurds make up almost 20 percent of the country's population of over 74 million and, like their fellow Kurds in Syria and Iraq, have long sought independent statehood.
Abdullah Ocalan, who has led the PKK since its inception, commands a fervent following and is the single most important figure in the organization. While the PKK doesn't represent all Kurds in Turkey, it does garner popular support
Large-scale conflict with Turkey's government started in 1984 when the PKK launched an armed insurgency against the state. Fighting in southern Turkey claimed thousands of lives on both sides during that early period. It further escalated in the 1990s with the PKK's use of suicide bombing as a tactic. In 1997, the United States placed the group on its list of foreign terrorist organisations, where it remains today
Turkish authorities finally caught up with Abdullah Ocalan in 1999, capturing him in Kenya's capital of Nairobi with help from U.S. intelligence. Before his arrest, the PKK leader had left his residence in Syria and traveled from nation to nation -- including Italy, Greece, Germany and Russia -- aided by sympathizers of the Kurdish independence movement.
Turkey's state security court first sentenced Abdullah Ocalan to death. But following enormous violent protests from the Kurdish population, not just in Turkey but elsewhere in Europe, his sentence was commuted to life imprisonment.
Abdullah Ocalan is housed in Imrali prison, which is located on an island off Istanbul and where he was the only prisoner until 2009
The PKK went into organizational decline after Abdullah Ocalan's capture
The Turkish government and the PKK made a number of attempts to begin a peace process throughout the 2000s, including holding secret meetings between 2009 and 2011 in Oslo.
President Erdogan announced the start peace talks with Abdullah Ocalan in 2012, and in early 2013 the latter signaled an immense shift in PKK policy by calling for a ceasefire with Turkish authorities
Braving nationalist anger, Erdogan introduced tentative reforms on Kurdish rights and in 2012 launched negotiations to try to end a PKK insurgency that has killed 40,000 people since 1984.
A fragile ceasefire had been holding since March 2013.