It has now been 22 years since Turkey became a candidate nation for membership of the European Union.
It has been a rocky, and ultimately fruitless, road. In 2018, negotiations were frozen over what the EU called Turkey’s backsliding with regard to democracy, the rule of law, and fundamental rights under President Recep Tayyip Erdogan.
In reality, negotiations had been frozen since far earlier. The EU wants Ankara to accept the reunification of the divided island of Cyprus. Turkey has refused to consider anything but a two-state solution for the island.
Even if Cyprus were not a red line for a number of European states, including Italy and France - not to mention Greece - there are a number of other seemingly intractable issues between Turkey and the European Union, most recently over refugees.
Ilke Toygur, analyst of European Affairs at Elcano Royal Institute, said the meeting with EU leaders is being held during tumultuous times in Turkey.
"Behind closed doors, the main (EU) message will be as long as you play along with foreign policy, there will be an improvement in the relations," she said.
Watch the Euronews video report in the player above.
Turkey is home to four million Syrian refugees and many more from elsewhere that want to reach Europe via its maritime border with Greece and Bulgaria. In 2016, the EU agreed to pay Turkey €6 billion to prevent Syrian refugees from crossing to Greece from Turkey.
Five years later, that money has run out and yet millions of refugees still live in Turkey and want to cross to Europe. Often when the EU has a falling out with Ankara - a weekly occurrence, it seems recently - Erdogan threatens to stop preventing refugees heading to Europe.
The Turkish president has proved time and again that he is willing to play hardball over the issue, even publicly encouraging migrants and refugees to try to access the EU via Greece.
Last year, Ankara enraged Cyprus over offshore drilling in its waters, prompting fears of a military confrontation between the old enemies, Turkey and Greece.
At times, Erdogan has appeared to have been simply trolling Europe with his policy shifts and proclamations. On 19 March, the EU heralded a productive video conference between Erdogan, European Commission President Ursula von der Leyen, and Council president Charles Michel.
In a statement, the EU side underlined the importance of sustained de-escalation and of further strengthening confidence building to allow for a more positive EU-Turkey agenda.
Just two days later, Erdogan announced that he was pulling Turkey out of the Istanbul Convention on domestic abuse by presidential decree, prompting an angry statement from EU foreign policy chief, Josep Borrell, who said Ankara was “sending a dangerous message”.
“We cannot but regret deeply and express incomprehension towards the decision of the Turkish government to withdraw from this convention that even bears the name of Istanbul,” he said.
But hasn’t only been Turkey’s actions that have slowed its European path.
Hostility to enlargement
The EU has undoubtedly cooled on the issue of enlargement, dragging its feet over everything from Romania being incorporated into Schengen to Montenegro joining the bloc. If a tiny, pro-Western state like Montenegro, population 660,000, can’t join Europe, what hope for a country of 82 million?
As such, Turkey’s EU membership is unlikely to be on the agenda during Von der Leyen and Michel’s trip on April 6.
The EU needs a new deal on refugees to prevent a repeat of the 2015 migrant crisis, and much of the debate will likely be over how much that is going to cost them.
Turkey is also a partner in ending the conflicts in Syria and Libya, in both of which it has been accused of having favourites, if not direct proxies. With Cyprus, negotiations are due to begin again in April - with the EU as an observer - and ensuring that Ankara doesn’t scupper them may be on Europe’s agenda.
As for the rule of law, Erdogan has shown no willingness to slow the tide of authoritarianism in Turkey, which critics say has been the hallmark of his 18 years in power. In February, Ankara launched a violent crackdown on student demonstrators despite threats of EU and US censure, while just a day before the summit, 10 retired admirals were arrested over criticism of the government.
This article has been corrected to say that negotiations with Cyprus will take place in April.